in all seriousness, PLEASE REMOVE ALL METAL OBJECTS FROM YOUR PERSON BEFORE YOU ENTER A MOSH PIT. this includes keys, studs, chains and any particularly stupid piercings you may want to have jutting out of your face. i've been scratched more times than i'd like to admit by some idiot that thinks it's a good idea to slam dance with metal studs in his jacket - a few times in ways that could have been messy if they hit the vein, if you see what i'm saying.
it's one thing to cut your own wrists, it's another to cut somebody else's because you throw yourself into a pit and can't figure out that you're full of sharp objects that have the potential to cut people. it's really just an issue of basic courtesy. but it's astounding how many people can't put two and two together.