Nope. LW is only an app that connects you to the Gnutella Network, which, in turn allows you to connect to other users/computers. Gnutella is an open network. LW is not responsible for any viruses you may pickup while downloading.

The best thing to do is: Learn the diff file sizes before downloading. Dont just click on something to download because users have a habit of sticking in viruses/trojans/worms which are very small files. Music files do not contain viruses.

If you are downloading illigal software, games or exe, those will most likely contain the viruses in them so beware and you can get a free anti virus cleaner fron snapfiles.com under their freeware section.