I mean, it exists on social media (so there’s that). There was a case where an American woman screamed at a French baker for refusing a crisp $20 bill as payment despite the fact she’s literally in France (where Euros are used as the main currency).
The stupidest one was from where an American guy was arrested in the UK for having open carry (firearms) where gun laws are strict, him using the excuse of “I don’t know the laws around here” didn’t work since he should’ve researched that beforehand.
I’ve seen a couple of things in Japan if that datapoint matters. Twice about accepting USD, and a few times getting mad about people not speaking English.
I’ve seen people (not just Americans, though) do things that are illegal here because they couldn’t imagine it being illegal in their home country. Cycling after any alcohol, cycling with earphones, cycling holding an umbrella, various waste disposal laws, picking up money and not reporting it (technically theft here even if it’s forgotten change in a vending machine, but that never gets enforced that I’ve seen), and just other minor stuff.
Americans in particular love to consider self defense as “if you say something I don’t like or throw the first punch, I can fight you” which is just wrong in Japanese law (only the amount of force needed, and no more, to get out of the situation to safety is legal; you can’t punch someone just because they punched you).
Edit: also pocket knives; we have very strict laws here and lots of Americans in particular (but I’m sure others) carry them without thinking and can get in huge trouble for it.
I mean people do illegal stuff in their home countries too because they don’t think it is illegal, but often it’s just that it’s not enforced.