Walls of death are insane. I've done tons of moshing but never participated in Braveheart re-enactments. In my younger days, I would get in the pits and slam against everyone else. In my later years, I reduced myself to perimeter work: keep the shape of the pit, help those up that have fallen, keep those out that don't want in, and scoop up and return lost items (mostly sunglasses, shoes and wallets). The only times I saw pits become violent were when those unfamiliar with pit etiquette would either attempt to injure others or would "hardcore dance" which involves swinging your arms around wildly while also kicking. These people would have justice doled out to them quickly because ain't nobody got time for that nonsense. Metal shows appear chaotic, but in my experiences, pits are actually pretty safe and organized.
I've seen Slayer, Slipknot, Amon Amarth, Behemoth, Lamb of God, Megadeth and dozens of other metal bands and have never witnessed the kind of things I've seen at rap concerts and, surprisingly, a Dave Matthews Band concert. DMB consisted of drunk frat boys who got way too liquored up and started fights while the rap shows were full of insecure tryhards who perceived every bump or nudge as an attack. It didn't matter if it was Outkast or Three 6 Mafia performing. People in the crowd were just itching for a confrontation.
