A reminder that the word "but" is one of the more dangerous in the language:
South Yorkshire’s police and crime commissioner, Alan Billings, said a case could be made for banning certain groups from demonstrating because of the community tensions they caused and the cost to the public purse.
“It’s very difficult to call for the banning of assemblies because, for all of us in politics, there will be times when we want to protest and be on the streets saying our piece,” he said. “It’s very hard for us to say that’s fine for us but not for somebody else but, with the far-right groups in Rotherham, I’d say a case could be made because they’re not just coming and saying their piece and going away.
It does not matter who and why nor even what. Free speech is one of these things which is indivisible. Either it extends to the ideas and people we don't like or we'll rapidly find that it is extended to those that we do.
There is a further point here, which is that the complaint stems from how much it costs to police such gatherings and demonstrations. Which brings us to the freedom of association, something just as important as that freedom of speech.
It is not for the police, nor the government, to stop us from assembling on the grounds of cost or, in fact, anything other than the danger of riot. Their job is to enable us in exercising our rights. And there's absolutely nothing at all more valuable that government does than the protections of our freedoms and liberties. Yes, even those of people we don't like.
It is, possibly, just about permissible to think of the state insisting we do not do these things on the grounds of cost. But that would have to be long after said state has dismantled all of the other things it spends money upon. For our reason for calling that state into being is that protection of our freedoms.