For a little bit now, League of Legends has started an initiative, where at the end of a match, a player gets rewarded by the others with praises of being helpful, friendly or displaying good teamwork or friendly competition. This is a post-game mechanic that is added beyond the typical "gg" at the end of a game.
The interesting thing is... that its working. I have seen an increase in the number of players saying thank you, glhf and in general at least saying hello. Where as before, that was something that existed and was slowly starting to slag off.
Now this does not mean that the opposite has been abandoned. Several, players still continue to swear, and deteriorate into juvenile actions. The fact, that such a system can at least encourage those who used to be nice to come back out of their shells, is huge.
I think that many more games should try to encourage things like this. Loading bumpers with, "Always start a game with a Good Luck, Have Fun," or "Help those who are new, don't forget you used to be new yourself!"
I've covered such actions before in an older post, but I feel that the company actively sending messages, being supportive will greatly help those who play that way to do so, regardless of the jerks and trolls. Let people be positive, let people who are negative be punished, and let the players dictate that.
Sure there are times when such mechanics will be gamed, but I think it is a great support to continual and traditional customer support and service. Between this initiative, and the tribunal, I think that Riot is taking several steps in the right direction, and that other MMOs should start looking to Riot on how to curb certain behaviors.