I was reading recently that some of the worst virus/trojan horse and related criminal activity comes out of Russia and that the Russian govt. is protecting the organized crime network(s) behind it all. Don’t know any details but apparently it is difficult or impossible for western LE to get any cooperation from Putin’s scumbags.
Just cut off Russia's connection to the 'Net.
A few years ago, China realized they had to clean up their act after a lot of system administrators started blacklisting Chinese IPs.
It's a lot harder to do now, as everyone would have to cooperate. Otherwise, they'll just set up a proxy in a "friendly" country. With the rise of 'botnets', you have to completely cut off their command/control link, or at least induce them to move out of Russia and into someplace within reach of law enforcement.