Well this topic has been discussed before many times.
My suggestion is delete those files as soon as you can. They aren't worth the hassle to get the license, and if you fill out the information to get one they are getting information on you.
You can search(upper right) for more information on the subject.
Here is one such result from a search.
http://www.gnutellaforums.com/showth...threadid=35225