Well, I think this planned protest will need to be supervised

But who will watch the Watchers?
I think we all should! What if everyone turns up in Hi-Vis jackets and starts 'kettling' the Police just to see how they like it! Think of the fun we could have with that

First, we could kettle them, then maybe cage a few hundred of them and deny them water, toilet facilities and medical care.
WOW! It could be a great day out! Perhaps a disabled Policeman will turn up in his wheelchair! Think of the fun we could have dragging him from that wheelchair, for his own safety of course, and dumping him on the cold,wet pavement.
Maybe we could get a discount from Sports World for a few thousand baseball bats, cricket bats etc, and use these instruments to 'subdue' any Policeman who thinks he has a right to protest and indulge in that most heinous of crimes: Free Speech!
I've no sympathy for the Police on this issue. They have shit on the public that pays their wages and now their masters have shit on them! Surely they knew it was coming? I wonder what they'll do when they find out whats happened to their cushy pension plan?