That's a tough question & not easily answered. I was asked that once before & I think my answer was to do a google search for the item. If it is from a formal business company & offered as a commercial product then you know it's most likely copyright. It can depend upon what you are looking to dwnld. You can develop techniques to find the right type of material to suit your needs.

If you wish to try Limewire (LW) then try the free version & see how you go. Any problems post here at the forum. You can get the free version from here: http://www.limewire.com/english/content/home.shtml If you don't like the program or don't like the concept of sharing that's fine. Try it & see how you feel about it. You can always uninstall it.