I think more than a few arenas have stopped playing "Rock N Roll Part II" but yeah, it's baffling that not all of them have. Maybe not even the majority have.
There's a Gary Glitter Bot on Twitter that'll retweet any mention of him and me & my friends occasionally tweet "Gary Glitter: Child Diddler" to get it retweeted. I don't know how or if we're helping the victims at all with that. :-\