Autofill, autotilt
So it seems we're now back in the Season 3 mentality, where anyone who thinks they'll have to support for even a microsecond will throw a legendary screaming shit fit over the prospect and sabotage the game for everyone, and possibly destroy their own computer in the process. The punchline this time around is the autofill system is fucking busted, because even though there's an extreme deficiency of supports and I go support/fill in an attempt to secure the position, I get autofilled as jungler. Then I get to spend twenty minute chunks watching the autotilted support scream obscenities and run into the enemy repeatedly.
The punishments need to be far, FAR harsher. Start banning people's IPs, ban any other accounts they'll jump on thinking they can Houdini their way out of trouble (I know you can identify individual computers, Riot). Do something to try and stop the people who think they can enter every game with a negative behavior and get away with it.