If someone signs in and gives up their privacy, I don't care. Where I do care is when someone with their pervert glasses captures an image of me at my kid's little league game and now I'm getting ads based on that.
I think you are fighting a losing battle if you choose to allow your kids to enter society.
Similar to how cops getting a warrant and tapping a single person's phone is different from the government spying on all citizens at all times.
Probably safer with a stranger considering children attacked by people they know.
People should be more worried at facebook scanning faces and linking photos to real identities.
So it'd be less likely that someone would film me and upload it to instagram or facebook.