We haven't gotten word as to why this happened, but it looks like Duo Cartoonist, the head behind some of the fandom's most beloved fandom animations, has officially closed their Youtube channel. This was after taking down a few of their videos with rumors circulating that it was due to fear of COPPA causing problems. We can't confirm that at this time, and they have expressed wishes to move on from pony work in the past, so it could be a mix of reasons. Fortunately there are backups of all of their work out there on the web.As the fandom gets older it's inevitable that some channels may become inactive, and with how sporadic youtube tends to be with policies and changes, it's a good idea to backup anything you want to keep.