+1
Any time you loan something to a friend, you risk not only losing that thing, but losing that friend.
That said, I rarely loan out discs I really love, except to family or very close friends. And even then, I'll heavily emphasize how careful I'd like them to be with it. Seems to work. Sometimes I don't get it back for awhile, but that's usually because it's not terribly important to have back right away.