To all the people being banned/chat restricted...
The new system is automated. It basically just checks chat logs for "bad words". If you don't type in chat, don't leave the match via esc key, don't stand still long enough for leaver buster to kick in, you will NOT receive a punishment.
This is what is wrong with the system and part of what has ruined this game. People know this. So they passively troll, ie they don't push lanes, they just roam and cs and buy items as they go, only defending towers to extend the time in game and refusing to /ff. Why? Because the system can't "detect" this, meaning Riot isn't going to put actual man hours (ie money) into the trolling problem in this game.
Some players are even taking lesson from pro trolls like Tyler1. Doing things like typing in chat to flamers, "why should i not push my lane?" when in reality it is 40 minutes in game and the enemy team is pushing another lane at the same time (they do this just in case Riot supp does look at the chat logs, giving the impression they aren't actually trolling).
As long as you buy items, cs and don't sit still long enough for leaver buster to kick in, you will never receive a punishment. From the automated system or Riot supp.
The rare case being that you intentionally feed/troll and someone records it and sends it directly to support via ticket.
This game has become 90+% troll because of this system.