There's a dodgy website called "Movietwists" that's hosting loads of my videos. The view count and comments are the same as on proper YouTube, but there are no ads. So theoretically I'm losing ad revenue if people watch it here instead. Ought I to be concerned, @TeamYouTube?
It seems to be some kind of unauthorised YouTube mirror. It even has some videos with a very small number of views. Definitely some call for concern there.