Muso.com just offered me peace of mind!! I spend so many hours tracking down people stealing my books and selling them online. It's a headache that every author is battling.
Muso.com is doing something to get that burden off your back. Go there, and sign up, for a small fee each month, they will alert you to all the links where these books are been listed. You then can go in and request a DMCA notice is issued. I signed up and there were 9 lines. 5 were down in half hour. 2 more went down within 2 hours. The others are pending.
I cannot recommend them enough!!