People are different. A lot of people enjoy messing around, filming fails and having a good laugh with their mates about it.
What you've got to remember is it's still a tiny, tiny percentage of the population of the world who are doing this. So just relax and get n with your life.
I agree with you in general, however, in principle, according to the basic laws of human stupidity proposed by an Italian economist Carlo M. Cipolla, stupid people are the most dangerous because 1) it's impossible to rationalize with them (as opposed to bandits whose motivations are known and can be understood), 2) because they can harm you without any reasons, at the worst possible time, and without any gain to themselves, and 3) there's no upper limit to human stupidity.