It looks like a new wave of copyright claim notices are happening these last few months on Youtube. Instead of the straight up take downs, pony music is being marked with something that removes their ads, and replaces them with ones that send the money earned to Hasbro instead of the musician behind it. If you want an example, check out this page. Both adsense and a link back to the Hasbro Studios Youtube Page are running at the same time after it was targeted with a claim. This is something that began hitting the "Lets Play" gaming community a few months ago, and is slowly making the rounds to just about everything else.
So far, it looks like only the videos with a pony image are being nailed. The automated program they use sniffs for copywritten images, video, and audio on things that are reported. There is a catch though; these images are including fan art and heavily photoshopped silhouettes like this one. Content ID is either getting incredibly smart, or notices are actually coming from Legal teams (Youtube or Hasbro). At first glance those Pinkie Pie's look more like octopuses than a pony. Fan art is especially surpising, as most of it isn't comprised of vectors ripped from the show and in a unique style a bot could never pick up.
For now, if you plan to upload music, it might be best to avoid using an actual pony image. While not everything is getting the axe, a good enough amount is. Hasbro's legal side works in mysterious ways, and in complete silence, so it's best to cover all of your bases and try to avoid them in any way you can.
