Booger sneered at her. "Lady, the ACLU is suing three hundred cops on 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 dinner when I knew that she'd been making falafel. Dad came home while we were still at the table and Mom and I took turns telling him the story. He shook his head.

"Lillian, they were just doing their jobs." He was still wearing the blue blazer and khakis he wore on the days that he was consulting in Silicon Valley. "The world isn't the same place it was last week."

Mom set down her teacup. "Drew, you're being ridiculous. Your son is not a terrorist. His use of the public transit system is not cause for a police investigation."

Dad took off his blazer. "We do this all the time at my work. It's how computers can be used to find all kinds of errors, anomalies and outcomes. You ask the computer to create a profile of an average record in a database and then ask it to find out which records in the database are furthest away from average. It's part of something called Bayesian analysis and it's been around for centuries now. Without it, we couldn't do spam-filtering --"

"So you're saying that you think the police should suck as hard as my spam filter?" I said.

Dad never got angry at me for arguing with him, but tonight I could see the strain was running high in him. Still, I couldn't resist. My own father, taking the police's side!

"I'm saying that it's perfectly reasonable for the police to conduct their investigations by starting with data-mining, and then following it up with leg-work where a human being actually intervenes to see why the abnormality exists. I don't think that a computer should be telling the police whom to arrest, just helping them sort through the haystack to find a needle."

"But by taking in all that data from the transit system, they're creating the haystack," I said. "That's a gigantic mountain of data and there's almost nothing worth looking at there, from the police's point of view. It's a total waste."