Its not a slippery slope, its carte blanche for a police force with a reputation for e.g. beating elderly people to death because they looked at them wrong (most famous being Ian Tomlison, but its fairly regular) to not have to hold back just simply because they run into a locked door.

And that is before you get into the court system, which if you need a quick primer, just look at the treatment of Julian Assange - and thats a "best case" for someone with millions of global supporters.

Uk police have targets to hit, they can't hit those targets going after real criminals, so they predominantly target people nieve enough to think they want to help them.

Of course they had to make running public forums a crime.