http://recode.net/2015/07/07/doing-something-about-the-impossible-problem-of-abuse-in-online-games/
"the vast majority of negative behavior ... did not originate from the persistently negative online citizens; in fact, 87 percent of online toxicity came from the neutral and positive citizens just having a bad day here or there.""... incidences of homophobia, sexism and racism ... have fallen to a combined 2 percent of all games. Verbal abuse has dropped by more than 40 percent, and 91.6 percent of negative players change their act and never commit another offense after just one reported penalty."