@jendrawscomics I at least scan through the thing looking for the parts most likely to be questionable (e.g. content licensing). I don't register on anything with too broad a license, and if I must register on such a site, I make sure to minimize the content I give them.
I'm also the sort to actually read through ToS changes, and I am always reluctant to register on sites whose ToSes state that they can modify it without notifying anyone. There's never a good reason for such a clause.