Me again,

I just though of this : what good self-respecting terrorist would use is real name on his library registration form?

"On the news today, police are on the lookout for a terrorist named I.P. Freely that blew up a school bus using a library computer. Last know good adress : 666 Al-Quaeda street,
(in the I-eat-babies-for-lunch district), Bagdad, Irak. Hobbies include eating babies and blowing up school buses."

LoveGravy, would you please explain to me how the FBI can catch smart bad-guys (not the bad-guys that you see in american movies) by spying on library users?