supposedly keep the riffraff out. Then if TSA has opened your bag, you are supposed to have a piece of paper in there saying so. Also, your lock should have a red/green thing that pops up or makes the color change, alerting you that the lock has been opened. I won't travel without my luggage being locked with a TSA style lock.

A fish and a bird can fall in love, but where will they build their nest?