Amazon has DRM but as others have pointed out, it's opt-in/opt-out by the publishers. In general Amazon is neutral on the matter (neither against or advocates DRM-free books).
I do dislike Amazon for going Mobi instead of ePub, but that's another discussion.
I think slightly more viable for "protection" would be watermarking.
Still, lots of smaller publishers do have DRM-free eBooks like Angry Robot Books or participating publishers at
http://weightlessbooks.com/