I am not able to post on the EUW boards, so I'm unable to provide that information. If the poster in question has questions about a ban, he or she is welcome to visit the Board Discord linked in the sidebar of the NA boards.
Looks like this dude has already contacted moderators. Judging by this post;
I have now chosen to report both you and Ulanopo (NA) due to how you have acted towards me and treated me, I find it unacceptable that you are trying to speak for me and tell others about my intetnions. Isnt there any rules about talking for others? Where I come from we have this thing called a "witch hunt" <- that is what you are doing towards me, maybe you know maybe you dont... it doesnt matter as it is an unacceptable behavior towards me. I wouldnt accept it IRL and I wont accept it here. Fact:It only happens on the internet, noone ever trying to speak for me irl, its only here... there is a reason for this.
I hope your co-workers are genuin and serious about this and get rid of these negative and destructive behaviors at once! They are not okey and should be condemned by everyone everywhere.
Was in response to a conversation directly with MuteAllFromStart in this thread and their speaking pattern was the same, it sounds like they've already talked with and been explained several times what they were banned for.