Community safety?

[No.3]

That's not entirely true as there are several ways, both chemical and electrical, to recover the markings from the sub-surface crystalline structure. I'm not a forensic metallurgist so don't know but I expect overstamping the ground area with a series of XXX's would make this a more difficult exercise.

Not as easy as you'd think, and a grinder generally doesn't piss around when it starts removing metal crystalline or not. Most stampings in firearms aren't deeply upsetting the metal to the point where there is a major structural change because of fatigue purposes.