I suspect that is misrepresentation
What worries me is that on both Facebook and Google you are *TOLD* that the tags have gone, but have they really? Given their apparent deepening connections with intelligence services I can imagine they follow the LinkedIn model of *cough* privacy: they still generate the data, you just no longer see it (try unsetting the filters in LinkedIn and see just what sot of trivia is broadcast by anyone in your network - the same goes for every move YOU make).
Masking makes more sense from the intelligence angle. It's also being rather creative with the truth, which feels more natural coming from companies that make their living with generating data - I don't trust sudden rollovers pandering for privacy when their entire business model is based on violating it..
So, back to basics - keep your personal data close and educate your friends. As any journalist can tell you (well, those that haven't been locked up yet for voice mail breaches), they tend to be your privacy leaks.. That goes for online too - there are still no real privacy laws for misleading your friends into giving out data about you. "Invite your friends to join Facebook" is the first gentle step to goad you into giving details: their email address. Just don't.