Multiplayer game League of Legends introduces report cards for banned users (na.leagueoflegends.com)

To give some light background, League of Legends is a popular game where two teams of 5 players are matching against each other. DAUs are in the millions, making moderation and banning difficult. Instead, players voluntarily participate in the "Tribunal", which is a jury-like system where players vote on abuse cases.

More details here: http://na.leagueoflegends.com/tribunal/