There was new legislation introduced regarding face coverings, if I recall correctly the police have the power to ask anyone on a protest to remove their face coverings.
I understand that a large group of mostly men, in black with their faces hidden appears to some (most) as intimidating.
As far as I am aware there were no arrests and the march was peaceful. The chants of whose streets, our streets would have been unsettling to some, but it is true, public streets belong to us all.
The protest organisers were astute in staying within the law, no banners, no markings etc.
As I posted up thread, we cannot ban marches because we (collective not personal) do not agree with the cause.
We either continue to have the right to peaceful protest for all, or the state bans all protest.
I do not agree with these protesters stance, but I respect their right to protest.