I see people doing this a lot in Deadlock, Valve's next game that's in pre-release stage now. There are all sorts weird and fun skins people play with through mods, some of them definitely not copyright-friendly.

I wonder how Valve will handle this once the game is ready to be released - will they just blanket ban the mods? (seems likely, and the community is even probably ready for it so will not be too pissed off at the move.) Or will their monetization route be something else this time, not "hats" like usual? (I'm hoping so, although I can't imagine what else it could be without being pay2win.)