What is the purpose of a lock for which all can obtain a key?
I am not using that lock for security outside the airlines...if a non-TSA employee got caught 1) with a TSA key or 2) messing with passenger luggage when not authorized; they'd have major issues.
The problem is (and I have know others this happened to as we all fly a lot and usually have heavy and nice bags) the TSA/luggage handlers become vindictive and thieves when they identify heavy bags or nice bags (mine is a top of the line TravelPro).
My brother has had tools stolen regularly through atlanta and kept complaining...it finally came to a major issue when his entire bag was checked onto the luggage belt, but never made it out to the baggage claim area. Some $5000 in loss.
There have been many TSA/handlers busted and the airlines do not want to take responsibility. If you are active on travel forums you will see a lot of this.
In my case, I am thinking they know my bag. It's not a common one plus it's not common to be carrying 70lbs in one. They cut my lock the last time. I think this time they were sending some kind of message by actually cutting the clasps off one zipper. The way the lock fits through both, one could not have been damaged alone. Also this time I upgraded the lock to something much harder to cut.
Either way they were TSA-approved locks with the key slot.