Regarding the Ban Methods used by Riot
Riot mainly bans players by account name (so, one specific account cannot be used). They also sometimes use IP bans to ensure that specific person cannot continue to play at all, buuut... IPs can be changed and that ban can be avoided. I've yet to witness Riot utilize a Computer ID ban though, and I'm genuinely interested as to why.
For those who don't know, every computer has its own MAC Address or Computer ID, and it's distinct to your specific computer and no other. So if I had a game and I banned your computer ID, your entire computer couldn't connect to my game. This in conjunction with an account ban and IP ban would totally lock you out unless you purchased a new computer (which is a lot of dedication just to play a game, right?)
So, Riot or another person of knowledge on their moderation systems, could you tell me why computer ID bans aren't used or are unpopular?
(TL;DR: Why can't Riot ban an entire computer based on its ID?)