Ripping DVDs for online video is now legal.
The U.S. Copyright Office published six new exemptions to the Digital Millennium Copyright Act´s (DMCA) anti-circumvention clause which make it easier for documentary filmmakers to legally use commercial DVDs. That material must be for "noncommercial videos".
The court wrote:
“Merely bypassing a technological protection that restricts a user from viewing or using a work is insufficient to trigger the DMCA’s anti-circumvention provision. The DMCA prohibits only forms of access that would violate or impinge on the protections that the Copyright Act otherwise affords copyright owners.”
It means also the ripping a DVD to make a backup copy is perfectly legal, ripping it to sell copies is not.