piatkow - 3:58 pm on Oct 25, 2011 (gmt 0)
They must be (hopefully) bound by some type of privacy act, outside of their own TOS, that doesn't allow for this.
Depends on the country of course. In Europe they couldn't partner with an ad network to do this unless you explicitly opted in to that clause, not hiding it in the small print. Of course if they set up their own ad networks then it would be a totally different matter.