OK, your post shows you to care about black lives. I also agree that with any rampaging mob in full on demo mode there are those who want to take advantage for a bit of looting, hooliganism or even so-called anarchists - who live in the world of the 1920/30s.
For me, I am not interested in any so-called British BLM 'movement.' What it means to me is the rush of concern in the States following a number of disgustingly wrong killings of black people at the hands of a febrile police force. That a large number of British people took that as a cue to demonstrate and, concurrently, raise the obvious issue of British slave traders, is a matter of pride to me. It's more than about time that this history was exposed for the evil that it was. But, I still say, BLM as a concept and movement for an end to racism in general and in the Police in particular, is a worthy cause. If there is a militant 'movement' harming that great cause by being violent and threatening, then I don't want to know it.