My previous post
described a case of TSA vandalism that I recently encountered and raised the question of why the note informing me that my luggage had been searched did not identify the particular TSA employee who searched it—that being an obvious and inexpensive way of discouraging both pilfering and vandalism. One commenter on the post described his own repeated experience, along lines similar to mine, and offered an interesting explanation.
The TSA agent is telling you not to bring stuff like that in your luggage anymore. Jars within jars containing some weird material need to be investigated by TSA agents. That means work and they don't like it. They are trying to teach you a lesson. The lesson is stop bringing that type of stuff on the plane with you.
Seen from this standpoint, the vandalism is not merely tolerated by TSA it is, at least tacitly, approved of. Which explains why TSA does not take obvious and inexpensive steps to prevent it.
It strikes me as a plausible conjecture but, short of getting a TSA inspector to confess, I cannot think of any easy way of testing it.