I get where you are coming from to an extent, my ex posted pics of my daughter (yes I said my) on his facebook they were pics I took. I asked him to make them private at least because they were public. I know I couldn't stop him from posting pics(he isn't around now yay!) but I could talk to him and at least ask him to make them private...maybe approach it calmly and ask him to make the video private, I think you can do that on youtube or something close to private. You can't control other people and what they post but you can be an adult about it and try to talk to them as such in a respectful way...in the end you have to be the bigger person for your kids.