[PirateDave]

Some locks do have alert features [0] so you should at least know it was opened. It won't stop a thief, but at least it lets you know when someone was looking. That is, if it makes it to your destination :-)

[0] http://www.amazon.com/Kolumbo-TSA-Lock-2-pack-BLACK/dp/B0106...

[matmann2001]

The comment above is saying that you can get into luggage without even touching the lock.

You just use something like a pen to break the zipper mesh. Sliding the zipper back and forth when you're done will re-zip it.