It does seem like it is a rogue ad that is impacting sites other than BYC. Now we have to try to track down the ad! If you happen to see which ad it is, what it looks like, etc. that would be good to know!
Ya, it's a terrible thing to do and we block anything like that. With that said, sometimes the bad stuff slips through our filters and we have to scramble to try and find out why.