Well, that's not the only way they're going to catch you.
According to this article, they're also going to be able to measure your biometrics, the expression on your face, the posture of your body, the sound of your voice and even the bumps on your noggin, and comparing them with an undoubtedly very large database, determine
At any rate, they'll catch you good, and foil your dastardly plans.
Of course, if your name's not Abdallah or something similar, you might not be noticed by the biometrics machine, for some reason.
Here's an example of the kind of thing the scanners could detect:
UPDATED to add: Boing-Boing's Cory Doctorow (no relation to E.L.) wrote this futuristic fable about what happens when the spooks take over Google. Like most futuristic sci-fi it's way heavy-handed, wall-to-wall exposition, dialogue that dances like a one-legged drunk and adverb-bound, but the good thing about it is how plausible his premise is.
Still, what're you gonna do, huh?