The latest TWIP (This Week In Photography) features an entertaining --and extremely cynical-- discussion about photographing children in public places. According to the conversation (starts about 6:30 into the show), a father in the UK was hassled by the police for taking pictures of his own children in a playground.
The show then shifts to talk about private vs public property and the rights of a free press. "We live in a world where folks need a scapegoat," says one of the TWIP guys, and photographers are on the state-condemned list.
Update: Here's the link about the "perv."