Require PK videos in media section to be posted uncovered as in, not allowed to cover anything in them or else deleted, this will help find the skill senders, and other players using things they shouldn't, those that used to post videos all the time prior to this and use the bad things will immediately quit posting, and you'll have your culprits
Covering could be limited to an area, of the screen, chat box only for instance.
"All videos must be posted with chat box only obscured and must capture the entire game screen."
-1 this if you use skill sender/flyhack and don't wanna get caught.