The DMCA's section on backing up movies on optical media is actually a bit of a catch 22. Backing up the movie for your own personal use is definitely legal under the Fair Use exception. However, optical media has CSS encryption and it is breaking the encryption that's illegal. So you can backup the movie, but getting access to the movie is illegal. So you can see the dilemma.
The DMCA was recently modified to include an exception to breaking encryption, but it's very limited in its scope. You can only create clips, not entire videos, and those clips are limited to:
2. Non-commercial videos
3. Educational use