] People who know they're being watched, and that their
] innocent actions can result in police scrutiny, are
] people who become scared to step out of line. They know
] that they can be put on a "bad list" at any time. People
] living in this kind of society are not free, despite any
] illusionary security they receive. It's contrary to all
] the ideals that went into founding the United States.

A fairly good article on why profiling doesn't work.

How We Are Fighting the War on Terrorism / IDs and the illusion of security