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 case

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-comments-arrest-prosecution https://www.theguardian.com/us-news/2017/may/18/facebook-com... https://www.bbc.co.uk/news/articles/cg7pyjxjxrvo https://www.bbc.co.uk/news/articles/cg7pyjxjxrvo https://www.nbcnews.com/tech/social-media/federal-agents-monitored-facebook-arrest-protesters-inciting-riots-court-records-n1231531 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.)