Before former NSA contractor Edward Snowden fled to Russia, the FBI demanded the immediate arrest - and extradition - of Snowden if he went to any Scandinavian nations. Snowden applied for asylum in Norway, but once FBI officials heard he would try to head to a Scandinavian country, they began pressuring Denmark, Sweden, Norway and Finland. Trying to leave Moscow, however, wouldn't be an easy task:
"The US Department of Justice is prepared to immediately draft the necessary paperwork to request the extradition of Snowden to the US from whichever country he travels to from Moscow," according to the letter. "The FBI expresses its gratitude... for any assistance that can be provided on this important matter."
It's likely the FBI and other government officials sent similar requests to many other European nations, which prevented Snowden from traveling outside of Russia.