The following chapter from Cory Doctorow's book Little Brother is used with permission via a license (details at end). Please support the author by buying his book (click the image below).
I wasn't the only one who got screwed up by the histograms. There are lots of people who have abnormal traffic patterns, abnormal usage patterns. Abnormal is so common, it's practically normal.
The Xnet was full of these stories, and so were the newspapers and the TV news. Husbands were caught cheating on their wives; wives were caught cheating on their husbands, kids were caught sneaking out with illicit girlfriends and boyfriends. A kid who hadn't told his parents he had AIDS got caught going to the clinic for his drugs.
Those were the people with something to hide -- not guilty people, but people with secrets. There were even more people with nothing to hide at all, but who nevertheless resented being picked up, and questioned. Imagine if someone locked you in the back of a police car and demanded that you prove that you're not a terrorist.
It wasn't just public transit. Most drivers in the Bay Area have a FasTrak pass clipped to their sun-visors. This is a little radio-based "wallet" that pays your tolls for you when you cross the bridges, saving you the hassle of sitting in a line for hours at the toll-plazas. They'd tripled the cost of using cash to get across the bridge (though they always fudged this, saying that FasTrak was cheaper, not that anonymous cash was more expensive). Whatever holdouts were left afterward disappeared after the number of cash-lanes was reduced to just one per bridge-head, so that the cash lines were even longer.
So if you're a local, or if you're driving a rental car from a local agency, you've got a FasTrak. It turns out that toll-plazas aren't the only place that your FasTrak gets read, though. The DHS had put FasTrak readers all over town -- when you drove past them, they logged the time and your ID number, building an ever-more perfect picture of who went where, when, in a database that was augmented by "speeding cameras," "red light cameras" and all the other license-plate cameras that had popped up like mushrooms.
No one had given it much thought. And now that people were paying attention, we were all starting to notice little things, like the fact that the FasTrak doesn't have an off-switch.
So if you drove a car, you were just as likely to be pulled over by an SFPD cruiser that wanted to know why you were taking so many trips to the Home Depot lately, and what was that midnight drive up to Sonoma last week about?
The little demonstrations around town on the weekend were growing. Fifty thousand people marched down Market Street after a week of this monitoring. I couldn't care less. The people who'd occupied my city didn't care what the natives wanted. They were a conquering army. They knew how we felt about that.
One morning I came down to breakfast just in time to hear Dad tell Mom that the two biggest taxi companies were going to give a "discount" to people who used special cards to pay their fares, supposedly to make drivers safer by reducing the amount of cash they carried. I wondered what would happen to the information about who took which cabs where.
I realized how close I'd come. The new indienet client had been pushed out as an automatic update just as this stuff started to get bad, and Jolu told me that 80 percent of the traffic he saw at Pigspleen was now encrypted. The Xnet just might have been saved.
Dad was driving me nuts, though.
"You're being paranoid, Marcus," he told me over breakfast one day as I told him about the guys I'd seen the cops shaking down on BART the day before.
"Dad, it's ridiculous. They're not catching any terrorists, are they? It's just making people scared."
"They may not have caught any terrorists yet, but they're sure getting a lot of scumbags off the streets. Look at the drug dealers -- it says they've put dozens of them away since this all started. Remember when those druggies robbed you? If we don't bust their dealers, it'll only get worse." I'd been mugged the year before. They'd been pretty civilized about it. One skinny guy who smelled bad told me he had a gun, the other one asked me for my wallet. They even let me keep my ID, though they got my debit card and Fast Pass. It had still scared me witless and left me paranoid and checking my shoulder for weeks.
"But most of the people they hold up aren't doing anything wrong, Dad," I said. This was getting to me. My own father! "It's crazy. For every guilty person they catch, they have to punish thousands of innocent people. That's just not good."
"Innocent? Guys cheating on their wives? Drug dealers? You're defending them, but what about all the people who died? If you don't have anything to hide --"
"So you wouldn't mind if they pulled you over?" My dad's histograms had proven to be depressingly normal so far.
"I'd consider it my duty," he said. "I'd be proud. It would make me feel safer."
Easy for him to say.
Vanessa didn't like me talking about this stuff, but she was too smart about it for me to stay away from the subject for long. We'd get together all the time, and talk about the weather and school and stuff, and then, somehow, I'd be back on this subject. Vanessa was cool when it happened -- she didn't Hulk out on me again -- but I could see it upset her.
"So my dad says, 'I'd consider it my duty.' Can you freaking believe it? I mean, God! I almost told him then about going to jail, asking him if he thought that was our 'duty'!"
We were sitting in the grass in Dolores Park after school, watching the dogs chase frisbees.
Van had stopped at home and changed into an old t-shirt for one of her favorite Brazilian tecno-brega bands, Carioca Proibidão -- the forbidden guy from Rio. She'd gotten the shirt at a live show we'd all gone to two years before, sneaking out for a grand adventure down at the Cow Palace, and she'd sprouted an inch or two since, so it was tight and rode up her tummy, showing her flat little belly button.
She lay back in the weak sun with her eyes closed behind her shades, her toes wiggling in her flip-flops. I'd known Van since forever, and when I thought of her, I usually saw the little kid I'd known with hundreds of jangly bracelets made out of sliced-up soda cans, who played the piano and couldn't dance to save her life. Sitting out there in Dolores Park, I suddenly saw her as she was.
She was totally h4wt -- that is to say, hot. It was like looking at that picture of a vase and noticing that it was also two faces. I could see that Van was just Van, but I could also see that she was hella pretty, something I'd never noticed.
Of course, Darryl had known it all along, and don't think that I wasn't bummed out anew when I realized this.
"You can't tell your dad, you know," she said. "You'd put us all at risk." Her eyes were closed and her chest was rising up and down with her breath, which was distracting in a really embarrassing way.
"Yeah," I said, glumly. "But the problem is that I know he's just totally full of it. If you pulled my dad over and made him prove he wasn't a child-molesting, drug-dealing terrorist, he'd go berserk. Totally off-the-rails. He hates being put on hold when he calls about his credit-card bill. Being locked in the back of a car and questioned for an hour would give him an aneurism."
"They only get away with it because the normals feel smug compared to the abnormals. If everyone was getting pulled over, it'd be a disaster. No one would ever get anywhere, they'd all be waiting to get questioned by the cops. Total gridlock."
"Van, you are a total genius," I said.
"Tell me about it," she said. She had a lazy smile and she looked at me through half-lidded eyes, almost romantic.
"Seriously. We can do this. We can mess up the profiles easily. Getting people pulled over is easy."
She sat up and pushed her hair off her face and looked at me. I felt a little flip in my stomach, thinking that she was really impressed with me.
"It's the arphid cloners," I said. "They're totally easy to make. Just flash the firmware on a ten-dollar Radio Shack reader/writer and you're done. What we do is go around and randomly swap the tags on people, overwriting their Fast Passes and FasTraks with other people's codes. That'll make everyone skew all weird and screwy, and make everyone look guilty. Then: total gridlock."
Van pursed her lips and lowered her shades and I realized she was so angry she couldn't speak.
"Good bye, Marcus," she said, and got to her feet. Before I knew it, she was walking away so fast she was practically running.
"Van!" I called, getting to my feet and chasing after her. "Van! Wait!"
She picked up speed, making me run to catch up with her.
"Van, what the hell," I said, catching her arm. She jerked it away so hard I punched myself in the face.
"You're psycho, Marcus. You're going to put all your little Xnet buddies in danger for their lives, and on top of it, you're going to turn the whole city into terrorism suspects. Can't you stop before you hurt these people?"
I opened and closed my mouth a couple times. "Van, I'm not the problem, they are. I'm not arresting people, jailing them, making them disappear. The Department of Homeland Security are the ones doing that. I'm fighting back to make them stop."
"How, by making it worse?"
"Maybe it has to get worse to get better, Van. Isn't that what you were saying? If everyone was getting pulled over --"
"That's not what I meant. I didn't mean you should get everyone arrested. If you want to protest, join the protest movement. Do something positive. Didn't you learn anything from Darryl? Anything?"
"You're damned right I did," I said, losing my cool. "I learned that they can't be trusted. That if you're not fighting them, you're helping them. That they'll turn the country into a prison if we let them. What did you learn, Van? To be scared all the time, to sit tight and keep your head down and hope you don't get noticed? You think it's going to get better? If we don't do anything, this is as good as it's going to get. It will only get worse and worse from now on. You want to help Darryl? Help me bring them down!"
There it was again. My vow. Not to get Darryl free, but to bring down the entire DHS. That was crazy, even I knew it. But it was what I planned to do. No question about it.
Van shoved me hard with both hands. She was strong from school athletics -- fencing, lacrosse, field hockey, all the girls-school sports -- and I ended up on my ass on the disgusting San Francisco sidewalk. She took off and I didn't follow.
> The important thing about security systems isn't how they work, it's how they fail.
That was the first line of my first blog post on Open Revolt, my Xnet site. I was writing as M1k3y, and I was ready to go to war.
> Maybe all the automatic screening is supposed to catch terrorists. Maybe it will catch a terrorist sooner or later. The problem is that it catches us too, even though we're not doing anything wrong.
> The more people it catches, the more brittle it gets. If it catches too many people, it dies.
> Get the idea?
I pasted in my HOWTO for building an arphid cloner, and some tips for getting close enough to people to read and write their tags. I put my own cloner in the pocket of my vintage black leather motocross jacket with the armored pockets and left for school. I managed to clone six tags between home and Chavez High.
It was war they wanted. It was war they'd get.
If you ever decide to do something as stupid as build an automatic terrorism detector, here's a math lesson you need to learn first. It's called "the paradox of the false positive," and it's a doozy.
Say you have a new disease, called Super-AIDS. Only one in a million people gets Super-AIDS. You develop a test for Super-AIDS that's 99 percent accurate. I mean, 99 percent of the time, it gives the correct result -- true if the subject is infected, and false if the subject is healthy. You give the test to a million people.
One in a million people have Super-AIDS. One in a hundred people that you test will generate a "false positive" -- the test will say he has Super-AIDS even though he doesn't. That's what "99 percent accurate" means: one percent wrong.
What's one percent of one million?
1,000,000/100 = 10,000
One in a million people has Super-AIDS. If you test a million random people, you'll probably only find one case of real Super-AIDS. But your test won't identify one person as having Super-AIDS. It will identify 10,000 people as having it.
Your 99 percent accurate test will perform with 99.99 percent inaccuracy.
That's the paradox of the false positive. When you try to find something really rare, your test's accuracy has to match the rarity of the thing you're looking for. If you're trying to point at a single pixel on your screen, a sharp pencil is a good pointer: the pencil-tip is a lot smaller (more accurate) than the pixels. But a pencil-tip is no good at pointing at a single atom in your screen. For that, you need a pointer -- a test -- that's one atom wide or less at the tip.
This is the paradox of the false positive, and here's how it applies to terrorism:
Terrorists are really rare. In a city of twenty million like New York, there might be one or two terrorists. Maybe ten of them at the outside. 10/20,000,000 = 0.00005 percent. One twenty-thousandth of a percent.
That's pretty rare all right. Now, say you've got some software that can sift through all the bank-records, or toll-pass records, or public transit records, or phone-call records in the city and catch terrorists 99 percent of the time.
In a pool of twenty million people, a 99 percent accurate test will identify two hundred thousand people as being terrorists. But only ten of them are terrorists. To catch ten bad guys, you have to haul in and investigate two hundred thousand innocent people.
Guess what? Terrorism tests aren't anywhere close to 99 percent accurate. More like 60 percent accurate. Even 40 percent accurate, sometimes.
What this all meant was that the Department of Homeland Security had set itself up to fail badly. They were trying to spot incredibly rare events -- a person is a terrorist -- with inaccurate systems.
Is it any wonder we were able to make such a mess?
I stepped out the front door whistling on a Tuesday morning one week into the Operation False Positive. I was rockin' out to some new music I'd downloaded from the Xnet the night before -- lots of people sent M1k3y little digital gifts to say thank you for giving them hope.
I turned onto 23d Street and carefully took the narrow stone steps cut into the side of the hill. As I descended, I passed Mr Wiener Dog. I don't know Mr Wiener Dog's real name, but I see him nearly every day, walking his three panting wiener dogs up the staircase to the little parkette. Squeezing past them all on the stairs is pretty much impossible and I always end up tangled in a leash, knocked into someone's front garden, or perched on the bumper of one of the cars parked next to the curb.
Mr Wiener Dog is clearly Someone Important, because he has a fancy watch and always wears a nice suit. I had mentally assumed that he worked down in the financial district.
Today as I brushed up against him, I triggered my arphid cloner, which was already loaded in the pocket of my leather jacket. The cloner sucked down the numbers off his credit-cards and his car-keys, his passport and the hundred-dollar bills in his wallet.
Even as it was doing that, it was flashing some of them with new numbers, taken from other people I'd brushed against. It was like switching the license-plates on a bunch of cars, but invisible and instantaneous. I smiled apologetically at Mr Wiener Dog and continued down the stairs. I stopped at three of the cars long enough to swap their FasTrak tags with numbers taken off of all the cars I'd gone past the day before.
You might think I was being a little aggro here, but I was cautious and conservative compared to a lot of the Xnetters. A couple girls in the Chemical Engineering program at UC Berkeley had figured out how to make a harmless substance out of kitchen products that would trip an explosive sniffer. They'd had a merry time sprinkling it on their profs' briefcases and jackets, then hiding out and watching the same profs try to get into the auditoriums and libraries on campus, only to get flying-tackled by the new security squads that had sprung up everywhere.
Other people wanted to figure out how to dust envelopes with substances that would test positive for anthrax, but everyone else thought they were out of their minds. Luckily, it didn't seem like they'd be able to figure it out.
I passed by San Francisco General Hospital and nodded with satisfaction as I saw the huge lines at the front doors. They had a police checkpoint too, of course, and there were enough Xnetters working as interns and cafeteria workers and whatnot there that everyone's badges had been snarled up and swapped around. I'd read the security checks had tacked an hour onto everyone's work day, and the unions were threatening to walk out unless the hospital did something about it.
A few blocks later, I saw an even longer line for the BART. Cops were walking up and down the line pointing people out and calling them aside for questioning, bag-searches and pat-downs. They kept getting sued for doing this, but it didn't seem to be slowing them down.
I got to school a little ahead of time and decided to walk down to 22nd Street to get a coffee -- and I passed a police checkpoint where they were pulling over cars for secondary inspection.
School was no less wild -- the security guards on the metal detectors were also wanding our school IDs and pulling out students with odd movements for questioning. Needless to say, we all had pretty weird movements. Needless to say, classes were starting an hour or more later.
Classes were crazy. I don't think anyone was able to concentrate. I overheard two teachers talking about how long it had taken them to get home from work the day before, and planning to sneak out early that day.
It was all I could do to keep from laughing. The paradox of the false positive strikes again!
Sure enough, they let us out of class early and I headed home the long way, circling through the Mission to see the havoc. Long lines of cars. BART stations lined up around the blocks. People swearing at ATMs that wouldn't dispense their money because they'd had their accounts frozen for suspicious activity (that's the danger of wiring your checking account straight into your FasTrak and Fast Pass!).
I got home and made myself a sandwich and logged into the Xnet. It had been a good day. People from all over town were crowing about their successes. We'd brought the city of San Francisco to a standstill. The news-reports confirmed it -- they were calling it the DHS gone haywire, blaming it all on the fake-ass "security" that was supposed to be protecting us from terrorism. The Business section of the San Francisco Chronicle gave its whole front page to an estimate of the economic cost of the DHS security resulting from missed work hours, meetings and so on. According to the Chronicle's economist, a week of this crap would cost the city more than the Bay Bridge bombing had.
The best part: Dad got home that night late. Very late. Three hours late. Why? Because he'd been pulled over, searched, questioned. Then it happened again. Twice.
Little Brother by Cory Doctorow is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License .