It ultimately boils down to who owns the signal.
You would love to have a system that scanned the world's photos and notified you automatically about people commenting on you. You don't necessarily want the government to have that same system.
You would love to have a system that scanned the world's photos and notified you automatically about people commenting on you. You don't necessarily want the government to have that same system.
Furthermore, how do you rectify disagreements over that trust? I may trust a multinational corporation (especially if I own stock in it and can vote on its directors), but you may trust your government, and our neighbor may not trust anyone.
Both of those questions need to be "solved" (if such a thing is even possible), but that's (obviously) a lot easier said than done.
So I would rather allow anyone to have access to face recognition software, than to allow using it only for illegal use. Because nobody can prevent it from being used illegally.