I think it is also about the expectations in one's mind of what is acceptable. For typical people signing up with Google/Facebook, firstly, the information being scraped is overwhelmingly large/indirect/hidden for them to realize the magnitude/gravity of it. Second, they "mentally" accepted/resigned to that "system" when they signed up.

However, in case of someone taking photo of a face without permission, a) and b) above no longer hold true - it is their face - totally tangible, something a lot more personal and something people hold much more dear than the last search query and they never "agreed" to it (neither explicitly nor in their head).