When you're out in public you're in public! It's literally the opposite of private.

Why would you expect to remain anonymous or private in such a situation?

Everyone has the right to record what's going on, out in the open. You want to add shutter sounds and recording lights to cameras? Sure. That doesn't violate anyone's rights. But don't go restricting people's rights just because you think you'll never have the need to record something happening right in front of you.