Tens of millions of Americans, usually supporters of the 2nd, have openly declared that having a firearm on you while at a protest is a crime punishable by death, and have done nothing to stand up against Trump, who has openly declared his hostility to the 2nd amendment multiple times now.

Bringing a rifle to a protest you expect to get hot, brandishing it about, and then shooting someone in self defense is perfectly fine, but having an every day carry firearm, getting held down by the president's personal paramilitary org, and being shot execution style is apparently fine.

I'm sick and tired of the stupid claims about how important the 2nd is while the very advocates of it only bring it up to talk about how much they want to shoot democrats.

A guy was arrested for a joke he posted on social media about Charlie Kirk. He spent some time in jail but ended up winning a lawsuit. So the answer isn't exactly 0 in the US

To be fair the other country routinely deploys military against citizens, and deports non-citizens for speech.

It's actually quite hard to say, as there are no official figures on arrests specifically for social media posts in either country. And lot of the specific cases that people point to in the UK (e.g. Lucy Connolly) have parallels in the US:

https://www.theguardian.com/us-news/2017/may/18/facebook-com...

https://www.bbc.co.uk/news/articles/cg7pyjxjxrvo

https://www.nbcnews.com/tech/social-media/federal-agents-mon...

(The figures that the American right give for "arrests for social media posts" in the UK are actually figures from certain police forces for arrests under various pieces of online communication legislation, many of which have nothing to do with social media.)