The Finnish context and the American one aren’t really comparable. The USA is an 18th-century project where there was little emphasis on ethnicity. Modern Finland, on the other hand, is the project of 19th- and early 20th-century nationalism where the independent nation would be a home for specifically the ethnic Finnish people, while still providing rights and recognition for the ethnic Swedes (and, by the late 20th century, for the Saami). Complicating matters still further, some of the ideologues of an independent Finland for Finns, were ethnic Swedes who "switched sides", as it were.
wassenaar10’s two posts above are quite reasonable and on-topic, though I can understand how they might sound odd or offensive to people unfamiliar with Finland.
Culturally Swedish speaking Finns are much closer to Finns than to Swedes, 90% of the time. Add to the fact that a majority of them are fluently bilingual, and I'd call it somewhat of a stretch to characterize them as "ethnic Swedes". Source: live in Finland, speak both languages.
There’s a big difference, though, between Finland Swedes from Uusimaa who are well on the way to total assimilation, and e.g. those from Nykarleby whose contact with the Finnish language is limited and who still look to Stockholm in certain ways.
I am pretty sure that "Linus is an ethnic Swede, can't have that" was destined to sound offensive also to a fair number of people familiar with Finland, and that this was a predictable result. You also in passing manage to cast aspersions on the legitimacy of Finland as a nation-state while revealing a comprehensive lack of familiarity with American history. Please join wassenaar10 in resisting the impulse to visit your parochial resentments upon us and most certainly do not do so while appealing for tolerance under the banner of our 'unfamiliarity' with Finland. We are familiar enough with trolls and do not need to know any more than that.
> cast aspersions on the legitimacy of Finland as a nation-state
I don't know where you got that from. Finland is no less legitimate than all the other European countries whose independence movements arose in the 19th century, like Poland or those which emerged from Austro-Hungary. Finland is a fairly typical European nation-state.
> a comprehensive lack of familiarity with American history.
Ethnicity did not play the same role in the American War of Independence as it did in the 19th-century European independence movements, for the simple reason that that new notion of ethnicity did not arise until the age of Romanticism and the years immediately preceding 1848.
> your parochial resentments
I don’t share the resentments to which wassenaar10 may allude. I am not saying that he is correct, only that his view is one that exists in the Finnish context.
> We are familiar enough with trolls
"Troll" has a very specific meaning in internet parlance and is not merely anyone that you think is wrong.
wassenaar10’s two posts above are quite reasonable and on-topic, though I can understand how they might sound odd or offensive to people unfamiliar with Finland.