Our servers are located outside the jurisdiction of ~ most EU countries.
What does this mean exactly? I, for example, am outside most EU countries, simply because I can be inside only one country at a time. Does this mean your servers are located inside the jurisdiction of at least one EU country?
Hi! - Our servers are not located in any EU country. BUT they may be under the jurisdiction of some (few) EU countries. That is why we wrote that "most" of the EU countries, not all.
The issue here is not geography per se, but of jurisprudence. Namely, in a friendly or unfriendly political relationship between the EU and the United States with the country in which we have deployed our servers. And the country where our servers are located is unfriendly to the EU and the USA.
Therefore: the US special services, together with the special services of some EU countries, will not be able to obtain a legal arrest warrant for our servers, since the local court (the court of the country where our servers are located) will not issue them an appropriate order due to international political disagreements/conflicts.
We hope that we have answered your question.

What does this mean exactly? I, for example, am outside most EU countries, simply because I can be inside only one country at a time. Does this mean your servers are located inside the jurisdiction of at least one EU country?
I believe they mean that their servers are outside of EU (not sure if by "EU" they implied "Europe" or "European Union")
and in that part of the world where they are located, most of "EU" countries do not have jurisdiction. Not having jurisdiction there probably means that no European law coercion can be applied in the country where servers are located -- or most of European countries do not have legal treaties with that country.
That's right, thanks.
