I've been to Burning Man. Its history is such that in the first couple of years it had no customs banning anything. A common interpretation is that this was due to the type of personality of the average attendee (the "we are all in this together" type). An alternative interpretation is that it was less about the predominant personality type (assuming there even is such a thing, as opposed to just situational influence) and just about the relatively low number of attendees (hundreds or single thousands at the time). As it grew to its current size (over 50 thousand attendees last year) more and more rules had to be introduced, and they even have a 'conflict-resolution' group called the Black Rock Rangers.