Easily - imagine your parents posting your fully nude pictures on FB? Would you be 100% ok with that, even 20-or-so years later?
There is a small but very vocal element in the UK who would be horrified by that, and who would call the police and child protection social services.
I know it's stupid, and that parents have photographs on their children in baths, but these people have caused some problems for parents wishing to take photographs. School sports days, school plays, your child playing at a playground or in the park - all of these have been made difficult places to take photographs at.
Luckily, it's less of a problem now than it was a few years ago.
The crux of the issue is that I'm not who I was. Baby chad_oliver was a different person.