I use the same screen name for everything so I don't have to remember several different screen names when signing in to things, or telling people what my screen name is for a certain platform. This means that I use the same screen name for YouTube, my youtube's twitter page, and even gaming screen names of games I play. The name could differ slightly because there's a chance that "Legacy" on it's own had already been taken, so I'll add some numbers to it. I don't have a FaceBook page for my YouTube channel because I use FaceBook just for keeping up with friends and family, so I do not use my screen name on that. Overall, I think that being consistent with your screen name across platforms can help viewers recognize who you are without having to remember several different screen names for the same person.