It is not clear to me from the article what in the world these "extremely disruptive tactics" are that cause "serious annoyance" are. A recent protest was mentioned as it relates to the Metro Police, but no details of what the protesters were doing that seemingly sparked this.

Does anyone, perhaps those from the UK, have more knowledge of what could possibly justify this slippery slope that could reduce the freedoms enjoyed by UK citizens?

I think it is self evident, but who is the arbiter of what is "seriously" "annoying" or "disruptive"? Is blocking traffic while remaining silent one of these crimes?