While the exact details obviously arent public, there are varying degrees of suspicious folk lists. There are no fly lists which you have to pretty much be a suspected terrorist. But there is a more minor list that it is believed you can get on by your web searches or maybe purchases and from what was released lately about the nsa your phone conversations. Im derailing this post but I voted for ron paul and have a pretty cynical outspoken view of our current political state and for some reason I got pulled out going to and coming from new york for a random pat down.
"hey bill, looks like this guy posts online about cops being bad guys, better check him out".
Probably a fluke though and im kooky. Im flying soon and Im anxious to see what happens.