> So if you dutifully input valid ages for your computer users, now any groomer with a website or an app can find out who's a kid and who isn't. You just put a target on your kid's back.

I'm not going to say that's impossible but the number of sites that do the right thing and reduce risk are going to vastly outnumber that. And 90% of those kids already have targets on their backs by virtue of the sites they visit.