The best thing to do with ...
this kind of miscreant is to completely ignore them. The rest of us normal people going about our normal daily business, should only change a couple of things...
1: Apply a total news blackout... do not listen to, or watch any news or current affairs broadcast for the next few days.
2: Do not buy a newspaper, or read the online versions.
3: If you normally work in this area, do not go anywhere near the Exel Centre... call in sick or book a couple of days off.
4: If you are a member or supporter of some protest group or another... talk a good game on the web etc. but on the day, just sit at home and twiddle your thumbs.
In my humble view this is the best way to react to this sort of agitation by politicians and police... As Margaret Thatcher once said, "do not give them the oxygen of publicity".