They are complete jokes.

Having said that, if you google around, you can find some web pages where people have made their own TSA keys by opening TSA locks and seeing what's inside. It looks like there is some variation in how terrible they are. For example TSA 004 seems like a complete total astonishingly ludicrous joke, whereas TSA 007 looks like merely an easily pickable lock.

But basically, anyone with pretty modest lockpicking skills will get into any of them.