I just made an experiment with my current smurf account and the real one. Here are the results:
Calling somebody a %%% multiple times in a game gets you a two week suspension.
Going 0/20 by constantly walking towards the fountain in a game, didn't even get a warning.
Does Riot realize that the second offense is actually worse than the first? People don't usually start games by flaming, they watch other people do things that frustrate them to the point of flame.
Punishment for trollers should be more severe than that of flamers, because a lot of flamers tend to be victims of trolls or simply Riots faulty matchmaking system.