Except that the chance of a direct attack from one of those countries is just about nil, unless you nab yourself a trojan or click on a phishing link. Blocking these ranges does what for you? It won't stop emails from these countries. You need different software for that. Almost all attacks hit hundreds of thousands or millions of IP addresses, and takes advantage of those machines that are not protected.
The truth of the matter is you have more to worry about from your own government than some random phishing scheme curtsey of CZ or some other European country. Most of the attacks I see are not from Russia, China, or Nigeria. They are typically from Czechoslovakia, Germany, etc. Or.. from somewhere in the good ol' U.S. And any attack worth a damn is going to not going to be hosted via those countries, as you must know. So again, blocking them does you nothing.
I've been doing computer related work for over 25 years - the only times I've had any direct attacks they were always within the U.S. (perhaps originating in another country). When I do security checks on computers, the # of poor practices, lack of updates, lack of browser security, etc. are much MUCH more pressing concerns.
Just saying.. I think blocking IP ranges does almost nothing at all. And it's funny someone might be wasting their time doing that, while happily downloading from torrentz sites, and not securing the many holes in their basic computer security. Btw.. if you must download, don't use torrentz.. use irc.