What constitutes a troll?

I see people reporting others for being trolls because they don't play the lane they get stuck with (last pick). How is that trolling? Is there some part of the league terms and conditions that says you have to play a certain lane? The "Summoners Code" (http://gameinfo.na.leagueoflegends.com/en/game-info/get-started/summoners-code/) does state that teamwork is essential and a needed trait in an eligible player, but it doesn't say that you MUST fill a lane " TRY to fill a niche in your team that hasn't already been filled....TRY asking for another player to fill the gap....". So if you don't play a lane that is given to you and you play another role you get banned. That would contradict the "Summoners Code". If so then you can't ban others because they don't want to play a pre-determined role. I have been banned for being "toxic" (creative judgment in my defense ) just to throw that out there, I believe riot should enforce a mute button at the start of the game to show players that it exists. I find it ridiculous that people report others for speaking their mind when in fact they neglect the mute button that is there to protect you against "toxic" players, the sole reason for its existence. The only argument for the justification of the mute button would be ??? what? if you don't use it to mute "toxic" players then you are using it to ignore your teammates. So my question for whoever is reading this goes as follow's; What constitutes a troll? How is not playing a pre-determined lane trolling" Why are people being banned for being "toxic" when a mute button exists? I know this is a semi-long reading, so thanks for reading, all responses are welcomed.

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