The magic of the blockchain

[Cross-posted at]

You may have heard that the world of finance is getting excited about the potential of the blockchain (Economist, Financial Times, Forbes) and wondered:

What is the blockchain? What problem does it solve?

The blockchain is the technology behind the digital currency Bitcoin, but it has wider applicability. It is a collection of mathematical, recordkeeping, and communication procedures that makes it possible to trade digital assets securely.

Why is that a big deal?

Think of how useful it has been to digitize all kinds of information over the past generation or two.1 Digital information can be transmitted from place to place at lightning speed (literally), stored indefinitely, duplicated endlessly, and analyzed, processed, and transformed automatically, all without any loss of fidelity. This was all flatly impossible until quite recently. When it became possible, it didn’t just make things faster and more efficient. It enabled the creation of entirely new ways to produce and consume information that never existed before, and new industries built on top of them. Think Twitter, YouTube, Uber.

But money hasn’t been digitized – and has therefore been left out of all the dramatic innovation that has happened elsewhere in the economy – because digital information can be duplicated endlessly, which is at odds with the key feature of money: namely, that once you trade it away, you no longer have it. Think about it: without that feature, money would be useless.

If you have something valuable to sell, and I want to pay you with some digital data that I call “money,” what’s to stop me from keeping a copy of that data and then spending it again with someone else?

The blockchain, that’s what.

That’s impossible

You may now be thinking, “There’s no way to prevent the copying of digital data,” and you’d be right. Even so-called copy-protected data, such as a movie on DVD, doesn’t work on the principle of actually preventing copying. (It works by scrambling the data and refusing to descramble it unless the playback conditions are kosher. You can copy the scrambled data as many times as you like.)

And yet the blockchain does manage to prevent “double-spending.” You might now expect to hear an explanation of how it does so in terms of prime numbers, one-way functions, asymmetric encryption, and other arcana. But those are merely the implementation details, which we’ll save for another article. The main idea is this:

I don’t give you digital data as payment. I give the rest of the world a signed statement saying I paid you.

This is a fundamental and surprising insight into the nature of money: the token of exchange doesn’t matter as much as that everyone agrees an exchange took place. When everyone agrees on that, then I can’t double-spend that token, even if I’ve made a copy of it, because whoever I try to spend it with will know that token is no longer mine to spend. And they’ll know that you can spend it… and you’ll know that they know it.

The money at the bottom of the sea

Here it’s worth taking a little digression into the story of the Yapese and their Rai stones.

The Yapese live on Yap, an island in Micronesia in the South Pacific. You may have heard of the giant stone discs that they use as a traditional form of money. Hewn out of limestone rocks on Palau, some 200 miles away, and standing on edge, they tower over their owners, who sometimes have to stand on tiptoe just to peer through the holes drilled in their centers.

These coins weigh thousands of pounds each. They can’t be kept in a coin purse or even stored indoors, so they are propped up for display in public places. When it is time to spend one, the coin never moves – that would be too difficult, and might damage the coin (or the mover!). Instead, news of the transfer filters out to the Yapese, who maintain an oral history of the ownership of each coin. This shared “ledger” of trades ensures that only the current owner of a coin can spend it, no matter where it’s physically situated.

In fact, a rai stone being transported from Palau to Yap by outrigger canoe once famously sank to the bottom of the sea in a storm. When the sailors got home without their cargo, the Yapese did not doubt the fact of its existence, and since its location didn’t matter, they proceeded to trade it just like their other giant coins.

Imagine that an earthquake strikes the island of Yap. No one is hurt, fortunately, but all the stone discs are dislodged and they all roll downhill into the sea. No problem – the rai economy could still continue! Now imagine that, instead of an earthquake, collective amnesia strikes the Yapese. No one can remember who owns what! In that case the rai economy is destroyed and actual economic value is irretrievably lost. This illustrates that, in a very real sense, the record of trades is the money.

That kinda makes sense


Think about depositing money in the bank. You go to the bank and hand the teller some cash. Does the teller put the cash in a box with your name on it? No. Some of it goes into a vault, mixed with everyone else’s money. Some of it is put to work in the form of loans. In what sense is your money still in the bank? In the sense that the bank maintains a record of what it owes you if you ever come asking for it.

(To keep the bank honest, you also maintain your own records – deposit receipts, a checkbook register, etc. Occasionally your records and the bank’s may disagree. We’ll come back to this idea.)

Don’t we already have secure digital asset trading?

In a word, no.

The problem is that there are multiple recordkeeping systems that have to be reconciled with one another. When you swipe your debit card at a gas station (say), you initiate a series of steps in which you, your bank, the gas station, the gas station’s bank, and the card-processing network all have to make updates to their records. For efficiency, those updates are usually batched together with others, and they happen at different times for different participants in this transaction. The updates get transmitted between and among the participants, and those transmissions produce acknowledgements that also get transmitted. Each party has to incorporate the others’ details into its own recordkeeping, and if everything doesn’t agree, there may need to be some sort of dispute-resolution step, unless the cumulative error is small enough that it’s not worth it and someone just eats the loss.

All of this transaction clearing and settlement is comparatively slow and expensive and happens long after you drive away from the pump. The gas station has some “counterparty risk”: it has let you have its gasoline without being sure that it will get your money. (But that risk is small compared to the value of letting customers pay this way, which is why the gas station accepts it.)

This is all because no one involved – not you, not the banks, not the gas station or the card network – can be quite sure at any given moment where the money is,2 only that if they follow these procedures, it usually ends up in the right place. Each entity therefore does its own recordkeeping as a check and balance on the others – just the same way that you keep all your deposit receipts (you do, don’t you?) in case your bank ever shows the wrong balance on your account.

How does the blockchain help?

The blockchain is a ledger that is immutable, distributed, and cryptographically secure.

  • Ledger means that it’s a historical record of trades;
  • Immutable means that once a trade is added to the ledger, it is permanent and unchangeable;
  • Distributed means that everyone gets a copy of it (and keeps getting updates as they happen); and
  • Cryptographically secure means that that everyone can trust what’s in it.

If the parties in the gas-station example were all on the blockchain, what would be the steps by which the gas station gets paid?

  1. You add a transaction to the blockchain stating that some funds that you control (because in an earlier transaction, someone else transferred them to you) now belong to the gas station.

That’s all! When you commit to the idea that the record of trades is the money, there is no separate clearing or settlement step needed. The trade is its own settlement. As soon as you add that transaction to the blockchain, you lose control over those funds and the gas station gets control over them. The gas station can now add its own transaction to the blockchain transferring those funds to someone else – and you can’t.3

Would you like to know more?

In the original Bitcoin blockchain, there is one type of asset – bitcoin – and a predefined way in which new bitcoins can be “minted.” It is possible to generalize the idea of the blockchain, however, so that it can encompass many different kinds of asset (dollars, airline miles, corporate securities, loyalty reward points) with differing rules for issuing units of those assets onto the network. The next article in this series will take a closer look at the mechanisms behind the blockchain (including explaining why it’s called a “blockchain”) and describe some reasons and ways to alter the Bitcoin blockchain to make it suitable for other uses.

  1. I like to think of that scene in All The President’s Men when Woodward and Bernstein have to thumb through thousands of Library of Congress call slips one by one by one, hour after hour after hour. Today a few tap-tap-taps at a computer terminal are all that’s needed. []
  2. To say nothing of what the money is – which, as we’ve seen, is the record of who has paid what to whom. In this example (and in the economy at large) that record is a kaleidoscopic agglomeration of many differing and overlapping records, some of which lag behind others, some of which will never agree. It’s no wonder people are confused about money. []
  3. Of course it isn’t quite that simple. To achieve the cryptographic security that allows everyone to trust the contents of the blockchain, it takes a little time for the transaction to propagate across the network and for other participants on the network to certify it. []

The flip-around thing

After seeing the film The Martian, my sister Suzanne posed a science question about it to me, one that I can imagine many other moviegoers had as well. Here’s (an edited version of) her question and (an elaborated version of) my answer. Spoilers ahead!

Q: ‎My very first thought when NASA finally realizes Watney’s still alive was, great! It’s only been 40-something days. Surely there’s a way for the Hermes crew to go back for him. And then I waited another hour before the movie caught up.

What I don’t understand is why that idea became such a big aha/eureka moment for that dude who thought of it, why the “top minds” at NASA rejected it, and why it took so long to get behind it as a plan. Why didn’t anyone think of it sooner? Why couldn’t they expedite the rescue by boosting thrusters or whatever‎ to do the flip-around thing earlier?

A: The movie was great (and very faithful to the book), but it could have done a better job of explaining why the Hermes-return solution was such a big deal.

Star Trek makes space navigation seem like steering sea vessels. Star Wars makes it seem like driving hot rods. Other movies, video games, etc. – and even Interstellar, which took pains to depict some exotic science accurately – give the impression that it’s just a matter of pointing your ship where you want to go, and going there. For better or worse, that’s the mental frame of reference that audiences bring to movies about space.

In fact space travel (given our present technology) is much more like firing a gun. The spaceship is the bullet. You get one main chance to aim correctly, and then BANG, off you go. After that there is no changing course. Tom Hanks puts it like this in Apollo 13: “We just put Sir Isaac Newton in the driver’s seat.” (Something no real astronaut would say, understanding that there is no time Sir Isaac Newton isn’t in the driver’s seat).

In fact it’s even harder than aiming a bullet because a bullet reaches its target, or misses, in fractions of a second. A spaceship bullet is aimed at something that’s months away, at a target that’s in motion, and it travels – or more precisely, falls – through a medium governed by gravity, where the sources of gravity – the Sun, the Earth, Mars, etc. – are all in motion relative to each other, creating ever-shifting “currents” tugging the spaceship this way and that.

Once the Hermes fired her engine for the return trip to Earth, that was pretty much that. It had almost no fuel left for other maneuvering. There was no “doing the flip-around thing.” It would have taken a fair bit of inspiration even to think of looking for a return-to-Mars trajectory (let alone a return-to-Mars-and-then-Earth-again one!) plus a lot of luck that one existed, plus a lot of work to actually find it, plus a lot of daring to attempt a critical resupply during the high-speed gravity-assist Earth flyby, all of which the movie depicts a little too simply.

Hopefully, the many cool science things that the movie does depict accurately will whet audiences’ appetites to learn more and thereby discover for themselves just how audacious and unlikely the rescue plan was. Meanwhile, go play with NASA’s interplanetary trajectory browser!

Remembering the past no guarantee of not repeating it

In February of 1992, Apple Computer flew me from Pittsburgh to California and put me up at the Cupertino Inn for a series of job interviews over a couple of days. I extended my stay in order to visit a few other companies too.

One of the companies on my list was a tiny e-mail startup in San Rafael called Z-Code. I was planning to visit them in the afternoon after spending the morning at a prominent computer magazine, interviewing for an editorial position. That visit went very well, and so had the interviews at Apple; and having driven from Cupertino to San Francisco for that interview, I now had a sense for how long the return drive would be, and how much farther out of the way a visit to Z-Code would take me.

If I hadn’t been such a Star Wars nerd I might have skipped it altogether. But I knew that Skywalker Ranch and Industrial Light and Magic were in San Rafael somewhere and I harbored a secret hope of spotting them as I navigated to my Z-Code visit. I visited Z-Code and, to my surprise, found that opportunity more compelling than the ones at Apple and at the magazine. Two months later I was living in California and working at Z-Code and the rest is history.

Now, almost a quarter century later, I’ve had a very similar experience. I interviewed successfully at a number of well-known medium-to-large-sized companies over the past several weeks but found a tiny startup – that I had almost dismissed, at first, as not worth my time – to be the most compelling. Tomorrow I begin at

Shut your mug

At Google (where I no longer work, as of about a month ago) there was a thriving culture of discussion on internal mailing lists covering every topic from politics to parenting to the latest developments in the high-tech industry. Certain topics, and certain modes of expression, were forbidden by Google’s legal team for fear of some opposing lawyer making expensive hay out of a Googler’s utterance, in context or out, in the discovery phase of the lawsuits that came Google’s way almost daily. An exuberant peon could write “Feature [X] is going to crush competitor [Y]!” and suddenly Google could be looking at a serious antitrust complaint, for instance. (For more on how companies can be on the hook for the innocent utterances of its employees, see Jamie Zawinski’s classic article about the “bad-attitude” and “really-bad-attitude” mailing lists at Netscape.)

All Googlers were required to take a training course annually to reinforce the rules surrounding internal online communication, but passion, arrogance, and ignorance could sometimes undermine that training, and occasionally someone would write something inadvisable.

At times like these, a member of Google’s legal team named Doug – who seemed to do little else but read internal discussion groups – would swoop into the thread and respectfully remind everyone to “communicate with care.” On one such occasion, his remarks transformed the thread into one all about him and his polite but firm reminders. When a couple of folks contributed short poems on the topic, I composed and posted this (1 May 2012).

Doug I am!
I am Doug!
Do you like to shut your mug?

I do not like to shut my mug.
I do not like to, I-am-Doug.

Would you, could you, if we’re sued?
Could you, would you, if we’re screwed?

I would not, could not, if we’re sued.
I could not, would not, if we’re screwed.

Will you, will you, on your blog?
Will you, will you, lest we flog?

I will not, will not, on my blog.
I will not, will not, lest you flog.

Would you like to in the press?
Try it, try! Don’t make a mess.

I would not like to in the press.
I do not think I’ll make a mess.

Could you shut your mug in tweets,
In Facebook posts, and in the streets?

I could not shut it in the streets!
Not in my posts and not my tweets!
I do not think I’ll make a mess
And will not shut it in the press
Not on my blog
Not lest you flog
Not if we’re sued
Not if we’re screwed
I do not like to shut my mug!
I do not like to, I-am-Doug!

You do not like it, so you say
Try it, try it, and you may

I do now like to shut my mug!
I do so like it, I-am-Doug!
And I will shut it in the press
And I will never make a mess!
And I will shut it in my tweets
In Facebook posts, and in the streets,
And if we’re sued
And if we’re screwed
And on my blog
No need to flog
I do so like to shut my mug!
Thank you, thank you, I-am-Doug!

Am I a man who dreamed he was a butterfly, or what?

Last night I dreamed I was at the beach with my kids. We saw a food shack with its menu painted on a board in front, and one item on the menu was a “Tomato Rahway.” “Do you know Tomato Rahways?” I asked my kids in the dream. “We had them when I was little. It’s an open-faced grilled cheese sandwich with a slice of tomato under the cheese.”

I was briefly awake in the middle of the night after that dream, and I marveled at how my subconscious was able to dredge up the memory of Tomato Rahways after perhaps forty years of not thinking that phrase even once.

When I woke up for real this morning, the first thing I did was a Google search for [tomato rahway]. 1 It doesn’t exist, at least according to the Internet, and it now appears my brain conjured out of whole cloth not only the phrase “Tomato Rahway” and the association with a very specific food item that I probably never even saw let alone ate, but also the idea, like a cherry on top, that it was an old childhood memory, which apparently it wasn’t.

What the hell, brain?

Anyway, I officially proclaim that the name for an open-faced grilled-cheese sandwich with a slice of tomato is now “Tomato Rahway.”

  1. In the process, I stumbled onto a Googlewhack for [“tomato rahway” -plum], which links to this. []

Kill Ralphie! saved!

[Cross-posted at]

In the 1980’s, students and faculty at Carnegie Mellon University were on the Internet, but there was no World Wide Web yet – no browsers, no websites, no Google, Facebook, or YouTube; in fact, no video and almost no graphics, just text. But there still existed social communities online, organized into discussion forums on numerous topics. Usenet was the biggest of these. Carnegie Mellon had its own internal collection of discussion forums called bboards.

One bboard was called “Kill Ralphie!” When someone posted to Kill Ralphie, they were contributing a chapter to an ongoing story about a hapless lad who is alternately placed in immediate mortal danger, then rescued, both in the most creative and entertaining ways possible. I was an enthusiastic participant back then, along with many others at CMU. Writing for an audience of fellow contributors was a formative experience for me that improved my prose and humor skills from “immature” to “slightly less immature.”

Well, guess what? Kill Ralphie! lives again! I’ve taken that old pastime and turned it into a fun new website. Please check it out, contribute chapters, and enjoy:

From the home office in Pittsburgh, Pennsylvania

There is nothing I can say about David Letterman that isn’t already being said in tremendous quantity, and occasionally quality, all over the Internet. (Example.) Nothing, that is, except to relate my David Letterman Dream.

Background: I was a David Letterman fan from the very start of his national TV career. I saw him as a new comic doing stand-up on The Tonight Show. I rejoiced when a snow day meant I could stay home from school to watch his short-lived daytime program. His HBO special, “David Letterman: Looking For Fun” seemed designed to appeal especially to me, personally. I was there for the first episode of Late Night, and many more thereafter. His arrival on late-night TV just as I began the slow transformation to adulthood assured me I was inheriting a hipper and more interesting world than the genteel one inhabited by Johnny Carson and my parents. I didn’t know then to call it “postmodernism,” I just knew that there seemed to be a secret joke at the heart of pop culture and Dave and I both got it.

A few years later, halfway through college and finally living in a place of my own, feeling alternately independent and lonely, my sleep-wake cycle shifted crazily late and life an unpredictable whirl of schoolwork, friends, and cherchez la femme, Letterman became my reliable daily refuge. His frequent willingness to expose the machinery behind Late Night — the offices, the studio, the local environs, the staff and crew — was the first clear indication I ever had, and a strangely reassuring one, that a future writing top-notch TV comedy awaited me if I wanted it.

In a nearby parallel universe, Dave and I were buds.

I visited that parallel universe once in the most vivid dream of that sleep-deprived period. I got onto the elevator at the ground floor of Rockefeller Center with Dave and several others, some celebrities, some not. We all chatted amiably. As the elevator rose, it also shrunk, because 30 Rock, it turns out, was a pyramid, and that’s what pyramids do to elevators. So at each stop a number of people were forced to get out. Finally it was just me and Dave riding the last few floors to the top. Together we hatched a scheme where I would come on Late Night as a guest. Dave would introduce me as a big celebrity. (“Ladies and gentlemen, a man who needs no introduction…”) We’d make up movie premieres, charity events, and awards ceremonies for me to describe having attended. The joke would be on the audience as they tried to figure out where they were supposed to know me from.

To this day I half believe that if I had ever actually befriended David Letterman and pitched that idea to him, he would have gone for it, and I’m just as sure that no one else on TV from then until now would have.

Made man

We made a man.

When the planets literally aligned for his first appearance, thirteen years ago today, Andrea and I hoped to make him smart, confident, hard-working, and respectful (despite having to guess at how one achieves that). We never dared to imagine we’d get funny, honest, handsome, inquisitive, thoughtful, athletic, resourceful, kind, generous, friendly, responsible, dependable, creative, and mature into the bargain, but that’s what we got.

We take some of the credit for laying the foundation, but most of that good stuff is all you, Jonah. We’re long past being merely proud of you. It is a privilege to know you.

When you click a YouTube link

Earlier today I gave a presentation about YouTube to seventh graders for “career day” at Jonah’s middle school. (Actually I gave it six times in a row to rotating classroomsful of kids, with the result that (a) I’m totally shredded and (b) I have even more respect for what teachers do all day every day.) Coincidentally it’s the tenth anniversary of the first YouTube video.

I thought fifth grade would be my last chance to appear cool to Jonah’s classmates on his behalf (and I’ve now given that presentation to Archer’s class too), but it looks like I have some coolness left after all. He even allowed me to walk to school with him and his neighborhood friends this morning:

Me: OK if I walk to school with you in the morning?
Jonah, shrugging: Sure.
Me: OK. Just wanted to make sure I wasn’t cramping your style or anything.
Jonah: What style?

Maybe YouTube lends me a little extra middle-school cred. Anyway, the presentation was well-received by most of the kids. It involved soliciting sixteen volunteers per class to read different parts aloud in a short little play I wrote. Each volunteer got a copy of the script with his or her part individually highlighted (which I did by hand earlier this week for all ninety-six copies I needed to hand out – eight pages each – and this in the middle of April, because I’m a glutton for punishment). I was a little worried about getting enough volunteers in each class, but I need not have been; the kids were down with whatever the YouTube guy wanted to do. I gave out my bribes anyway: YouTube stickers and pens.

I was the narrator. Everyone in the class who didn’t volunteer for one of the other parts became “All the buttons and menus.” After we performed the scene, the teacher displayed a web page I had prepared containing a YouTube link and we watched – hopefully with a little better understanding now of what was going on behind the scenes – as she clicked it and Dramatic Chipmunk played. It took a split second to perform all the actions we’d just spent eight minutes dramatizing.

We didn’t get to the song I included at the end of the script. I didn’t expect to but included it anyway as a little lagniappe for the kids. I hope some of them are singing it now; I know I am.

After the sixth presentation, I thanked the teacher for hosting me. She complimented me on the scene I had written. “Thanks,” I said, “but after six repetitions the words have lost all meaning.” She replied, “Welcome to the world of teaching.”

Porn talk

My older son is closing in on 13 years old, has Internet access, and wears the same size shoes as I do. So I figured it’s time to have the Porn Talk with him.

I sat down to write a bullet list of talking points that I wanted to be sure to cover, but it came out in essay form instead. It’s reproduced below. Note the careful omission of judgmental and heteronormative language. If the values expressed are similar to yours, please feel free to repurpose this for your own parental porn talk.

There are good things about porn, bad things about porn, and in-between things about porn. It’s important to know about all of them before you get too involved with it.

First, the obvious. Porn can be fun. It’s exciting, it’s arousing, it’s a sort of “preview of coming attractions” before your actual sex life begins. It can help you learn about what sexual things you like and what things you don’t at a time when experimenting with other people is not possible (or at least not a good idea). It can answer some of your questions about sex, ones that maybe you’re too embarrassed to ask, or ones you simply didn’t think of. Being interested in porn is normal and OK. I’d be more concerned about a 13-year-old boy who wasn’t.

Now the not so obvious. Most porn is very different from real-life sex. In porn, the men and women have perfect bodies, are easily excited, and are always up for anything. They do not worry about pregnancy or about sexually transmitted diseases. This is a fantasy. You should not expect real sex to be just like porn any more than you’d expect real archaeology to be like Raiders of the Lost Ark. In real life, bodies aren’t perfect, people aren’t always in the mood, and sometimes you or your partner will say “ow” or “stop” or “no, I don’t want to do that.” I don’t mean that real-life sex isn’t amazing – it often is. It’s also sometimes just OK, and sometimes it’s even bad, like everything else in real life.

There is a serious problem that exists among some people who look at porn: they can develop unrealistic expectations about sex and about their partners. When things aren’t just like what they learned in porn, they get disappointed and disinterested. This can really interfere with their intimate relationships and mess up their lives. This doesn’t mean that you should accept a partner who disappoints you. The point of dating is to find someone with whom you’re compatible, who is into the same things (sexually and otherwise) and whom you find exciting. It’s OK to want a little fantasy in your sex life. But if all you know is porn, you risk closing yourself off to the wider, richer world of real-life sex.

Beyond that, there are worse problems. One is the problem of porn addiction, which is a real thing to be feared. You can become addicted to anything that gives you pleasure. It’s a biochemical change in the brain, which is what makes it so difficult to reverse. (You can read more about it here.) This is why we say that things should be enjoyed “in moderation.”

How can you tell the difference between innocent enjoyment on the one hand, and problematic addiction on the other? It’s actually pretty easy. When it starts interfering with other parts of your life, it’s an addiction. You may act towards other people in ways you wouldn’t normally choose to. You may skip activities in which you would normally participate. You might perform poorly on schoolwork or other tasks that you could usually do well. You definitely want to avoid getting addicted, because once you have an addiction, breaking it is very, very hard. To avoid addiction, exercise control over when you look at porn. Don’t let it exercise control over you. To reverse addiction, you first have to be able to acknowledge it exists, which can be hard all by itself. (A good rule of thumb: if you ever find yourself insisting, to yourself or others, that you don’t have a problem, that’s a sign that you probably do.) Seek help from someone, and get yourself involved in one or more different activities to divert your brain’s attention from what it’s craving.

Another serious problem is that, although there’s plenty of porn out there depicting joyful and even loving sex between consenting partners, there is also unfortunately a lot of the opposite: porn that is humiliating to someone, or degrading, or even violent. Porn with one or more of the people clearly not enjoying themselves. Sometimes it’s just an act, but much more often the people in this kind of porn are trapped in a life that’s little better than slavery, and the people producing this kind of porn are genuinely evil. Stay away from this stuff. Not only does looking at it encourage the scum that makes it; the bad vibes can take you to a dark place, messing up your head and your future sex life.

Some porn is actually illegal – illegal to make, and even illegal to look at, and people go to jail for it all the time. This does not apply to most normal porn featuring consenting adult men and women, but even that exists in a grey area where very many people disapprove of it, sending the police and the courts after them at every opportunity. (A great movie about this, which is also a true story, is The People vs. Larry Flynt.) As a result, the whole porn world is sort of semi-legal, and that invites certain kinds of scam artists. Beware of identifying yourself in any way to any porn site. If you are invited to chat, ignore it. Don’t answer survey questions. If you are offered a free signup to some new site, ignore it. Definitely do not respond to requests for photos or video of yourself or others. Disable “browser cookies” if possible. I can show you how. And do not download files; they are almost guaranteed to turn your computer into part of a criminal botnet under the control of Russian gangsters!

The point of all this is not to scare you or to be a killjoy. It’s only that if you’re not aware of this stuff and you’re not careful, it’s all too easy to land on content you’re better off avoiding, or to mess yourself up in a variety of ways. Forewarned is forearmed.

The most important thing is to remember that you can talk to me about any of this any time you like. If you have questions, if you see anything that bothers or worries you, if you have anything you want to express, I’m here. I promise never to embarrass you and to keep everything just between us. Don’t forget, I was a 13-year-old boy once too, and I was also every age you’re going to be for the next few decades. There’s bound to be some info in my head that you’d find helpful, and even when there isn’t, sometimes all you need is someone who’ll listen.