Unless you're getting music that is distributed under a Creative Commons license, the content you're getting is more than likely illegal. Hate to break it to you, but that's not supported here.
More about what you can share with Limewire:
There will probably be another post from a moderator saying this, but I thought I'd beat him or her to it.
Hey does anyone know if you could put songs from limewire on your player or if it would be a long process or not.