Can't the normal-people cops do something about this?

I've seen coverage of this - Muslim protestors in London's Whitechapel section threatening to punish booze-selling shop owners with 40 lashes - in several outlets, and still, I have not seen any statement from a public official to the effect that he city's government will not brook any kind of assertion of play-like authority on the part of non-governmental groups.  Isn't there someone on the scene saying, "Like hell you will"?