The "MADE IN ANGER" on the silkscreen cracks me up every time I see it. The juxtaposition of a silly message w/ my experience that only "SERIOUS TEXT" goes on PCB silkscreens makes for total hilarity to me.
I've never personally done it, or seen any in the wild, but it seems more likely to get away with? On a commercial product, something silly on a silkscreen is quite likely to be noticed by someone without a sense of humor.