if you stay logged in
If you log out they don't get the global tracking info, but it's a PITA cleaning out cookies and disabling the scripts every time, then re-enabling same when I want to use the youtube account, which is almost never. In fact I just uploaded my first video last week, and now have a grand total of 2 up there.
Granted almost no one would bother to the extent I go.
BTW my reference was after installing a system for a client. I try to get as many sites blocked as possible, swiftly. I don't know what a lot of them do afterward, but there's not a lot of facebook or other 'social' stuff going on. They're mostly busy business folk.
Some do use gmail, they're definitely among the 'big data.'
