Interestingly enough, there are multiple exit nodes in Russia, as far as I know, law enforcements aren't taking them down
They just have a Russian ASN and IP space but it's still located in Norway.
This was 2017 however and I'm surprised too that crackdown on other exit nodes didn't follow.
Likely run by Russian intelligence services or their catspaws and therefore heavily monitored and logged.
US intelligence likely run their own tor nodes as well.