Sorry - so much misinformation....
I don't understand how anyone was abused like that by TSA. I have never used a TSA lock on my lockable, hard sided luggage because either the locks are built internally into the luggage itself (see the Americase above or any modern Delsey lockable hard sided luggage, for example) and there is no place for a padlock or I used (on one particular case) my own, extremely durable padlocks, big ones, not those silly, little things. The problem seems to be that TSA doesn't understand it's own rules and neither do the airlines.
Back in the day the airlines required you to declare your firearms and show it was unloaded. Then they figured out it wasn't their job to check so TSA started doing. Now, depending on the airport, you get one of these:
1. Airline personnel check the gun, give you the tag, you put it into the suitcase, lock it, and they take the luggage.
2. Airline personnel issue you the tag, you toss it into the luggage, lock it, TSA takes it, x-rays it, done and done.
3. Airline personnel check the gun, give you the tag, you put it into the suitcase, lock it, and they escort you to TSA where they check it again - or not, as the case may be. It will be x-rayed. Sometimes they ask you if the tag is inside.
4. Airline personnel hand you the tag after you make the declaration and they take the bag and wheel it to TSA while you walk alongside, TSA takes it, ensures that the tag is inside, you lock it, they give you the key, they x-ray, done and done.
There are a couple of other variations but you get the point. I've seen them all, including the time they took my locked suitcase and tossed it onto a conveyor belt and I protested, saying there was a gun and a procedure, they said don't worry about it.....