Oh, hey, I've got those blocked already :) Assorted robots, notably including ahrefs whose distinctive behavior pattern is to first pick up pages and then get robots.txt. Presumably followed by "Darn! I could have got robots.txt in the first place and made myself look good. None of those pages was disallowed anyway."
I wouldn't have the heart to block Russia. Sometimes I get people from Yandex looking for pictures of rats ;)