As has already been pointed out, however, what about cases where a police officer is inside your home, responding to a break-in? Do you want footage of the tour of the out/in-side of your home on YouTube? Do you want the toughest moments of the lives of decent people chronicled for everyone to watch?
Let me draw a parallel from a world I know - Canada's health care system. It is publicly paid for, like the police, and as such, records and information "belong to the people". However, when I call an ambulance, that record is considered confidential, and requests from the public for access must be justified. A process exists for releasing those documents, and patient privacy is a major component of it. I don't see why, with a police encounter, it couldn't work similarly. Yes, the risks are higher, since police sometimes like to hide things, but involving a neutral third party whose access can't be overridden by police, could mitigate those.