The other opt out option is to not sign in. Sign in to gmail, sign out, then sign in t YouTube. Of course that's pretty much a waste of time so the tracking in this case is no biggie. I don't see the danger. It seems like a lot of hype to me though I could be just missing something. Ever since Facebook started this when they decided to track every web user ever and now Google seems to be forced to compete. The lesson is, once one site does it the rest will be following close behind. To stop this sort of thing before it spreads we'll have to throw a SOPA-style tantrum. It might be way too late now though.