The UK (and Europe's) free speech problem

I don’t follow the US news closely, but in this post ( Reluctantly — Fuck Texas - #1017 by smithsb ) reference is made to a student being arrested for mocking (the death of) Kirk. Is this not a violation of the bill of rights? Doesn’t look like she was protected from being arrested.

BTW I agree that the UK law and its application are worrisome, but that doesn’t take away issues like this in the US.