Hi Dee R.,
Limewire doesn't control the content of the network. People are free to share whatever files they want to. a lot of the viruses have been put on the network by ill meaning people and by organizations like the riaa/mpaa to try and disrupt the file sharing networks. The most you can do is try to avoid them by learning what to look out for.
Watch the file sizes. Don't d/l files smaller the 1MB(1000KB), unless it's an image file or text file that you know is small. Also be careful d/ling program/game files(exe, zip ect.) They are risky and full of viruses. Always scan your files before you open them.
This is a good thread:
WARNING: Viruses on network you should be aware of!.
