After the post by chrisj about his friend having his padlocks cut by the TSA, my initial thought was WTF. However, some quick research into the TSA revealed that this is common practice.
I also came across the information about approved locks you posted. Whilst looking into this further, I was surprised about the number of people complaining about using TSA approved locks and still having them cut.
So if you have fire arms, what happened to my friend, you shouldn't have TSA approved locks. Because the "keys" for them are everywhere. Supposedly it's only the supervisors that have the keys. However they can't stop the line long enough to get the person, and the bolt cutters are right there... At leas that was the result of what I found out when I looked in to it.