An account on Youtube that apparently owns everything. They will delete your videos if they find just the smallest reason to believe you have used material that belongs to them. The thing is, almost none of the content is really theirs! You can try to dispute the claim, but that will most likely get you banned from Youtube, because almighty UMG thinks that it can just go around and pwn everyone and everything. Oh, and don't even think about messaging them, because they won't reply.
Universal Music Group: Oh, no! Someone uploaded a 5-second clip of a song we don't own! BANBANBAN!