I’ve seen posts online or memes about it, mainly discussing American people who think the internet as a whole is US-centric despite the topic at hand taking place in another country (nothing to do with America), for example: someone wrote the date format as 30/10/2020 (using the EU format) but some American was like “THE CORRECT WAY IS 10/30/2020” when they fail to realize that user is not American at all.
Is US defaultism real when they travel abroad? They assume the $ is legal tender worldwide in countries where their own currency is used more (the only thing that’ll work is exchanging it but not for direct transactions). I’ve heard an American woman went on a tirade whilst in France as the cashier refused a $20 bill when the prices are in EUROS (WTF?) or being like “SPEAK ENGLISH!” in non-English speaking countries.
Oh its real. In communities where there is an explicit rule about only being for local things will always have a post somewhere about the numpties and the poster always says something along the lines of “This non us place is mentioned in the US article so its OK to post.”
Look at any help community, the numpties will post about a hyper specific problem but not where they are, or just an abbreviation expecting everyone to know what MS or OK is.