Ah, Threads and some other lower quality social media are full of people making snarky comments to users from the States, saying something to the effect of “we are also in the Americas, so we’re Americans, you’re a US-ian”.

It all basically stems from the fact that in Spanish, the demonym for people from the US is “estadounidense” (United-Statesian) whereas “America” is used to refer to all of North and South America as a regions. People are too dumb to realise “America” has a different connotation in the two languages and it devolves into flame wars.