With concerts you have a lot of teenagers attending and concert promoters want to have as safe an environment as possible so is security adequate enough? At some concerts they ban certain clothing such as gang clothing, is this a good practice?

The worst security at a concert was back in the late 60's when the Rolling stones hired the Hell's Angels to provide security for $500 worth of beer- though both sides subsequently denied it.

Four people managed to wind up dead. A couple of people got killed in an auto accident amidst the chaos, and one person managed to drown in a drainage ditch. The famous death, of course, was Meredith Hunter who was stabbed multiple times and kicked to death on film right in front of the stage by Hell's Angels during the Rolling Stones set.