I mean it's implicitly known that anything you post on the internet is public property, but legally that is not the case. Portrait law (at least in my country). You can't just take someone's portrait and use it for your own gains.
Couldn't this same argument be made for Google reverse image search? Reverse image search someone's face and you're likely to get links to places that photo is located; potentially including links to different photos of their face, as well.
They're likely mirroring local copies of the photos as well when they show you the link (in case a link later 404s or changes), but so is Google reverse image search, I believe.
If your position is that both things are wrong, that's fine, but would Google then basically have to remove the entire feature? Or prevent searches for any photo containing any faces?