https://www.youtube.com/watch?v=-LDzOi1dyAA
Be Safe!
An Israeli security agent writing for Cracked did a pretty good ditty about it too.
http://www.cracked.com/blog/7-reasons-tsa-sucks-a-security-experts-perspective/
One of the biggest problems is of the TSA is they primarily screen luggage. Sure, as the guy in the video points out, you go through those full body scanners and have to take off shoes and coats, but real emphasis is on what you're carrying. Moreover, they really only screen you once, making a huge chokepoint at security screening that creates two halves of an airport: the pick up drop off side where anyone can walk into, and the "safe" side that's already been screened. Unfortunately, it just creates a false sense of security.
Creating a false sense of security is the primary function of government. It pays well.