Recently there is a guy in Russia took photos of random persons on metro and used a “face” search engine to find those people on vk.com (biggest social network of Russian). Creepily, he found all of them there!!
And today, Facebook shows me this one
It is a blurry photo and Facebook could identify my friend for certain, they ask “want to tag xx – Yes – No”. This means that they know for sure that is face of my friend.
It is only a matter of time it knows any one and be used by worse guys.
Everything yours 