Feeding by proxy needs to be addressed. NOW!
I just got out of a game in which my mid laner literally gave up at 5 minutes. He got tilted because "no ganks, gg" while our jungler was busy literally tower diving bot then securing dragon. He proceeded to push out side lanes for the remainder of the game, only fighting enemies when they engaged him (occasionally securing a kill). We won because our vayne had like 15 kills at 30 mins.
This kind of behavior needs to be addressed, and Riot lacks both the technical prowess and the will to do so. This kind of trolling is 100% detrimental (nearly as much as actually int feeding), but it is undetectable by the bot, as the kda, cs, and even items show what appears to be an active player. Riot, you MUST institute a peer review system for trolling reports. Let US (the people who are actually affected by this shit) be the judge of what is and isn't trolling. The line is far too fine for a bot to handle these reports in any capacity. Other games have this kind of peer review system where players can watch gameplay of the match in question and pass judgement on whether the player was trolling or cheating (also good for policing hackers, not that that's a huge issue in LoL). Why not join the 21st century instead of backsliding away from the Tribunal in the first place?