I'm sorry that I can tell you the answers to your questions as I have often wondered the same thing. What people get out of doing that to other people? I just don't understand what kind of pleasure someone would get by giving someone else a virus and possibly destroying their computer. I also have no idea if Limewire can ban those people. I can offer you a few pieces of advice about the things you are downloading that people have offered to me. The first one is if there is a strange title to it (eg. ===this===, or usually if someone's name is in the title, like mosby, or sponsored result) stay away from those. Also, if the file size doesn't look right. The main one I have come across as having a virus is the size 851.7 KB. It usually has some sort of toolbar attached, and even after the virus is neutralized you only have a message stating something to the extent of Integrated Systems Toolbar, and no program. I find the most virus's with the programs that I download, not usually music files. I have also been told that virus's can easily be attached in a zip file, so after downloading I always scan the file with my antivirus before unzipping the files. There is a sticky on here about virus's and I will try to find it for you and post the link to the thread.

good luck,
moe