Interestingly the biggest recent tweet/speech-related outcry I remember in the UK was a case of US authorities not seeing the funny side: http://www.dailymail.co.uk/news/article-2093796/Emily-Buntin...
He even sticks a "literally Hitler!" on the end for good measure.
Either way the mods took this article off the frontpage.
As a side note, the border security do not operate under the same laws as the US courts/police. It's a grey area where they can arbitrarily deny you for looking at them the wrong way. Free speech doesn't apply at border crossings. In addition noone was arrested domestically. Not the best analogy.