Even with those bad files and spammers you do not know if you are blocking only them. They might have dynamic IP's. Then they will have a differnt IP next time, and some poor soul that is sharing the top of the line will be blocked instead.

Of Course that is up to you, but I find it much better to just use the keywordfilter, look at size and use Bitzi, and of course some common sense. If it looks to good to be true, it probably is. It has worked well for me at least. In the over two years of using Limewire, I have had one bad virus-like file. Not a real virus but this one made my cpu go to 100% every time I got close to it. Had to use the command-promt without starting windows to be able to remove it.