This chapter is dedicated to New York City's Books of Wonder, the old-est and largest kids' bookstore in Manhattan. They're located just a fewblocks away from Tor Books' offices in the Flatiron Building and everytime I drop in to meet with the Tor people, I always sneak away to Booksof Wonder to peruse their stock of new, used and rare kids' books. I'm aheavy collector of rare editions of Alice in Wonderland, and Books ofWonder never fails to excite me with some beautiful, limited-editionAlice. They have tons of events for kids and one of the most inviting at-mospheres I've ever experienced at a bookstore.
Books of Wonder: 18 West 18th St, New York, NY 10011 USA +1 212989 3270They took me outside and around the corner, to a waiting unmarkedpolice car. It wasn't like anyone in that neighborhood would have had ahard time figuring out that it was a cop-car, though. Only police drivebig Crown Victorias now that gas had hit seven bucks a gallon. What'smore, only cops could double-park in the middle of Van Ness streetwithout getting towed by the schools of predatory tow-operators thatcircled endlessly, ready to enforce San Francisco's incomprehensibleparking regulations and collect a bounty for kidnapping your car.
Booger blew his nose. I was sitting in the back seat, and so was he. Hispartner was sitting in the front, typing with one finger on an ancient,ruggedized laptop that looked like Fred Flintstone had been its originalowner.
Booger looked closely at my ID again. "We just want to ask you a fewroutine questions.""Can I see your badges?" I said. These guys were clearly cops, but itcouldn't hurt to let them know I knew my rights.
Booger flashed his badge at me too fast for me to get a good look at it,but Zit in the front seat gave me a long look at his. I got their division91number and memorized the four-digit badge number. It was easy: 1337is also the way hackers write "leet," or "elite."They were both being very polite and neither of them was trying to in-timidate me the way that the DHS had done when I was in their custody.
"Am I under arrest?""You've been momentarily detained so that we can ensure your safetyand the general public safety," Booger said.
He passed my driver's license up to Zit, who pecked it slowly into hiscomputer. I saw him make a typo and almost corrected him, but figuredit was better to just keep my mouth shut.
"Is there anything you want to tell me, Marcus? Do they call youMarc?""Marcus is fine," I said. Booger looked like he might be a nice guy. Ex-cept for the part about kidnapping me into his car, of course.
"Marcus. Anything you want to tell me?""Like what? Am I under arrest?""You're not under arrest right now," Booger said. "Would you like tobe?""No," I said.
"Good. We've been watching you since you left the BART. Your FastPass says that you've been riding to a lot of strange places at a lot offunny hours."I felt something let go inside my chest. This wasn't about the Xnet atall, then, not really. They'd been watching my subway use and wanted toknow why it had been so freaky lately. How totally stupid.
"So you guys follow everyone who comes out of the BART station witha funny ride-history? You must be busy.""Not everyone, Marcus. We get an alert when anyone with an uncom-mon ride profile comes out and that helps us assess whether we want toinvestigate. In your case, we came along because we wanted to knowwhy a smart-looking kid like you had such a funny ride profile?"Now that I knew I wasn't about to go to jail, I was getting pissed.
These guys had no business spying on me — Christ, the BART had nobusiness helping them to spy on me. Where the hell did my subway passget off on finking me out for having a "nonstandard ride pattern?""I think I'd like to be arrested now," I said.
92Booger sat back and raised his eyebrow at me.
"Really? On what charge?""Oh, you mean riding public transit in a nonstandard way isn't acrime?"Zit closed his eyes and scrubbed them with his thumbs.
Booger sighed a put-upon sigh. "Look, Marcus, we're on your sidehere. We use this system to catch bad guys. To catch terrorists and drugdealers. Maybe you're a drug dealer yourself. Pretty good way to getaround the city, a Fast Pass. Anonymous.""What's wrong with anonymous? It was good enough for Thomas Jef-ferson. And by the way, am I under arrest?""Let's take him home," Zit said. "We can talk to his parents.""I think that's a great idea," I said. "I'm sure my parents will be anxiousto hear how their tax dollars are being spent —"I'd pushed it too far. Booger had been reaching for the door handle butnow he whirled on me, all Hulked out and throbbing veins. "Why don'tyou shut up right now, while it's still an option? After everything that'shappened in the past two weeks, it wouldn't kill you to cooperate withus. You know what, maybe we should arrest you. You can spend a day ortwo in jail while your lawyer looks for you. A lot can happen in thattime. A lot. How'd you like that?"I didn't say anything. I'd been giddy and angry. Now I was scaredwitless.
"I'm sorry," I managed, hating myself again for saying it.
Booger got in the front seat and Zit put the car in gear, cruising up24th Street and over Potrero Hill. They had my address from my ID.
Mom answered the door after they rang the bell, leaving the chain on.
She peeked around it, saw me and said, "Marcus? Who are these men?""Police," Booger said. He showed her his badge, letting her get a goodlook at it — not whipping it away the way he had with me. "Can wecome in?"Mom closed the door and took the chain off and let them in. Theybrought me in and Mom gave the three of us one of her looks.
"What's this about?"93Booger pointed at me. "We wanted to ask your son some routine ques-tions about his movements, but he declined to answer them. We felt itmight be best to bring him here.""Is he under arrest?" Mom's accent was coming on strong. Good oldMom.
"Are you a United States citizen, ma'am?" Zit said.
She gave him a look that could have stripped paint. "I shore am,hyuck," she said, in a broad southern accent. "Am I under arrest?"The two cops exchanged a look.
Zit took the fore. "We seem to have gotten off to a bad start. We identi-fied your son as someone with a nonstandard public transit usage pat-tern, as part of a new pro-active enforcement program. When we spotpeople whose travels are unusual, or that match a suspicious profile, weinvestigate further.""Wait," Mom said. "How do you know how my son uses the Muni?""The Fast Pass," he said. "It tracks voyages.""I see," Mom said, folding her arms. Folding her arms was a bad sign.
It was bad enough she hadn't offered them a cup of tea — in Mom-land,that was practically like making them shout through the mail-slot — butonce she folded her arms, it was not going to end well for them. At thatmoment, I wanted to go and buy her a big bunch of flowers.
"Marcus here declined to tell us why his movements had been whatthey were.""Are you saying you think my son is a terrorist because of how herides the bus?""Terrorists aren't the only bad guys we catch this way," Zit said. "Drugdealers. Gang kids. Even shoplifters smart enough to hit a differentneighborhood with every run.""You think my son is a drug dealer?""We're not saying that —" Zit began. Mom clapped her hands at him toshut him up.
"Marcus, please pass me your backpack."I did.
Mom unzipped it and looked through it, turning her back to us first.
94"Officers, I can now affirm that there are no narcotics, explosives, orshoplifted gewgaws in my son's bag. I think we're done here. I wouldlike your badge numbers before you go, please."Booger sneered at her. "Lady, the ACLU is suing three hundred copson the SFPD, you're going to have to get in line."Mom made me a cup of tea and then chewed me out for eating dinnerwhen I knew that she'd been making falafel. Dad came home while wewere still at the table and Mom and I took turns telling him the story. Heshook his head.
"Lillian, they were just doing their jobs." He was still wearing the blueblazer and khakis he wore on the days that he was consulting in SiliconValley. "The world isn't the same place it was last week."Mom set down her teacup. "Drew, you're being ridiculous. Your son isnot a terrorist. His use of the public transit system is not cause for a po-lice investigation."Dad took off his blazer. "We do this all the time at my work. It's howcomputers can be used to find all kinds of errors, anomalies and out-comes. You ask the computer to create a profile of an average record in adatabase and then ask it to find out which records in the database arefurthest away from average. It's part of something called Bayesian ana-lysis and it's been around for centuries now. Without it, we couldn't dospam-filtering —""So you're saying that you think the police should suck as hard as myspam filter?" I said.
Dad never got angry at me for arguing with him, but tonight I couldsee the strain was running high in him. Still, I couldn't resist. My ownfather, taking the police's side!
"I'm saying that it's perfectly reasonable for the police to conduct theirinvestigations by starting with data-mining, and then following it upwith leg-work where a human being actually intervenes to see why theabnormality exists. I don't think that a computer should be telling the po-lice whom to arrest, just helping them sort through the haystack to find aneedle.""But by taking in all that data from the transit system, they're creatingthe haystack," I said. "That's a gigantic mountain of data and there's al-most nothing worth looking at there, from the police's point of view. It'sa total waste."95"I understand that you don't like that this system caused you some in-convenience, Marcus. But you of all people should appreciate the gravityof the situation. There was no harm done, was there? They even gaveyou a ride home."They threatened to send me to jail, I thought, but I could see there was nopoint in saying it.
"Besides, you still haven't told us where the blazing hells you've beento create such an unusual traffic pattern."That brought me up short.
"I thought you relied on my judgment, that you didn't want to spy onme." He'd said this often enough. "Do you really want me to account forevery trip I've ever taken?"I hooked up my Xbox as soon as I got to my room. I'd bolted the pro-jector to the ceiling so that it could shine on the wall over my bed (I'dhad to take down my awesome mural of punk rock handbills I'd takendown off telephone poles and glued to big sheets of white paper).
I powered up the Xbox and watched as it came onto the screen. I wasgoing to email Van and Jolu to tell them about the hassles with the cops,but as I put my fingers to the keyboard, I stopped again.
A feeling crept over me, one not unlike the feeling I'd had when I real-ized that they'd turned poor old Salmagundi into a traitor. This time, itwas the feeling that my beloved Xnet might be broadcasting the locationof every one of its users to the DHS.
It was what Dad had said: You ask the computer to create a profile of anaverage record in a database and then ask it to find out which records in thedatabase are furthest away from average.
The Xnet was secure because its users weren't directly connected to theInternet. They hopped from Xbox to Xbox until they found one that wasconnected to the Internet, then they injected their material as unde-cipherable, encrypted data. No one could tell which of the Internet'spackets were Xnet and which ones were just plain old banking and e-commerce and other encrypted communication. You couldn't find outwho was tying the Xnet, let alone who was using the Xnet.
But what about Dad's "Bayesian statistics?" I'd played with Bayesianmath before. Darryl and I once tried to write our own better spam filterand when you filter spam, you need Bayesian math. Thomas Bayes wasan 18th century British mathematician that no one care about until a96couple hundred years after he died, when computer scientists realizedthat his technique for statistically analyzing mountains of data would besuper-useful for the modern world's info-Himalayas.
Here's some of how Bayesian stats work. Say you've got a bunch ofspam. You take every word that's in the spam and count how manytimes it appears. This is called a "word frequency histogram" and it tellsyou what the probability is that any bag of words is likely to be spam.
Now, take a ton of email that's not spam — in the biz, they call that"ham" — and do the same.
Wait until a new email arrives and count the words that appear in it.
Then use the word-frequency histogram in the candidate message to cal-culate the probability that it belongs in the "spam" pile or the "ham" pile.
If it turns out to be spam, you adjust the "spam" histogram accordingly.
There are lots of ways to refine the technique — looking at words inpairs, throwing away old data — but this is how it works at core. It's oneof those great, simple ideas that seems obvious after you hear about it.
It's got lots of applications — you can ask a computer to count thelines in a picture and see if it's more like a "dog" line-frequency histo-gram or a "cat" line-frequency histogram. It can find porn, bank fraud,and flamewars. Useful stuff.
And it was bad news for the Xnet. Say you had the whole Internetwiretapped — which, of course, the DHS has. You can't tell who'spassing Xnet packets by looking at the contents of those packets, th............