[Satam]

Are you implying that this is a problem that arises specifically from Facebook's targeted advertising? I genuinely don't think that's the case.

It doesn't really matter if ads are served to everyone or if they are shown only to a targeted demographic - either way, only people who are interested will click on them. Also, I think it is safe to say that, roughly, it is only the efficiency of clicks per ad-view that will increase if one uses targeted advertising.

So, if the act of clicking a targeted advertisement does not in itself somehow "transfer" any more identifying data than a click on a regular ad would, which I don't think it does, then what's the problem?

[kurthr]

Facebook is incentivised to collect and collate product data because it can then sell targeted ads for those humans. As long as the most cost effective path to those targets is through Facebook, and the aggregate target volume is high enough they will make money. Distributing the login data is just advertising.