Drawing attention to yourself by speaking too loudly, chatting with every stranger in sight, complaining about why they don't offer American cuisine in a country that isn't America or not even attempting a few words of the native language of the country they're in are typical American tourist traits.
Of course, some level of cringe from locals is expected in any major tourist city, but Americans sometimes try their hardest to put the spotlight on them. Unfortunately, the world is more than your "Eat, Pray, Love" tour. Stop screaming at a stressed server for a side of Ranch dressing on your pizza, Melissa! You're in Rome, not the Times Square Sbarro!
So, when a Reddit user asked, "How do you spot an American tourist "from a mile away?" non-Americans were ready to share the behaviors they've noticed from tourists that are a dead giveaway that they're from the United States.