Facebook I hate cyclists group infiltrated!

This.

The law does not entitle me to the opinion that I can cure cancer with basil and star anise - well it does, but only if I do not express that opinion. You cannot police people's thoughts and it would not be a good thing to do so even if you could. But you can and should police the expression of their opinion if those opinions are unjustified, unjustifiable and dangerous to others.

The law absolutely entitles you to express that opinion, so you're wrong about that.

And no, there are virtually no circumstances where you should police the expression of any opinion, so you're wrong about that. The most effective way to discredit someone with objectionable opinions is to let him or her voice them. So you're wrong about that too.