Like all profiling programs, this one mainly consists of innocuous behavior which has no connection to terrorism or crime of any kind. Instead, it simply substitutes what someone deep in the bowels of the TSA feels like is probably related to terrorism. Things like carrying an almanac, or too many pre-paid calling cards. The fact that such profiling programs are laughably ineffective is so obvious I'm not going to even do the minimal work necessary to provide citations (fun challenge: find a single citation supporting any profiling program!), because these programs are basically putting a slight, psuedo-scientific sheen on what is basically a Jeff Foxworthy routine.
So the next time you're flying, remember that if you do any of these things, you just might be...a terrorist.