American's in Britain have been warned by the US Embassy to keep their heads down during Donald Trump's visit to the UK and to 'exercise caution in the vicinity of large gatherings'.
As my Canadian Colleague finds out regularly, to British ears American and Canadian accents pretty much sound the same so American's can just pretend they're Canadian, and everybody likes a Canadian like they did at the height of the Iraq War and the dumbass in the White House then that we were getting uppity about was George W Bush.
Canadian's don't like you doing it because there is a chance that a real Canadian will get mistaken for an American pretending to be a Canadian so my colleague has come up with a guide to not make yourself known, top being try and speak quieter, Americans apparently, are much louder and boastful than your average normal person.
Personally i think as long as you don't turn up at the protest with a picture of Trump, a cowboy hat and a Confederate flag then you won't have a close up view of how great our socialised Health Service is.
If you do find yourself surrounded by angry Brits, my advice would be to shout 'it's coming home' which will almost guarantee you safe passage to a burger place where all the other Americans will be, they will be the ones shouting as they talk to each other about how they wish they could have bought their guns with them.