As an avid photographer, I have had a few run ins with people who think that photography in public places is either illegal or gives them a right for general abuse.

Quoting Rogier van Bakel:

"To be clear, there is no law against taking photos — or video — in a public space. Not in the U.K., anyway. Not in the U.S., either. Know your rights, and assert them. Let them atrophy, and, like never-used muscles, they begin to disappear."

Below is a video of London Community Support Officers behaving in a disgraceful way, projecting so much aggression from the first, that I guess most people would immediately back down.  This sort of behaviour is disgusting but hopefully displays possibly a form of correct manner to handle these matters.