Please use some other archive/mirror service than archive.is; suggestions about a replacement are welcome.
This is what access to archive.is looks like
The story (as per archiveis on Twitter) about geoblocking Finland goes something like this:
The archive.is guy (Some Russian Name according to whois info) tries to enter Finland (probably over the Russian border) and has an "incident" with a customs officer. He provides no details about that "incident" and customs have privacy policies, so no info or confirmation if anything took place. Guesses about the type of "incident" range from confiscated cigarrettes/alcohol to illegal drugs, which are the typical cases of custom "incidents". He then proceeds to take childish revenge on (EU) customs policies by blocking access from an entire country. When questioned about it, he first tries to convince people the government of Finland is involved in some conspiracy targeted on himself, because he's obviously such a threat and Important Person and that Finnish authorities blocked his site, which are easily proven false. Then he goes on with other excuses to block the country (including insane conspiracy theories).
Of course it's up to the owners of a site to choose their audience, but I think this makes it pretty clear the site isn't run by a sane individual and anything unpredictable may happen with it. I also think it's questionable whether a site operated by untrustworthy people like that should be encouraged to exist by directing traffic to it.
Sources / threads on the topic:
TL;DR The guy running archive.is is a delusional conspiracy nut, who blocks access to his site randomly, including entire countries (in this case Finland).
Edit: Removed actual name extracted from archive.is' whois record