IANAL, but even if we assume the act of backing up a DVD to hard drive is legal, it's not clear to me how one could legally use the resulting copy without somehow circumventing CSS.
And with only narrow exceptions that probably don't apply here, this act of circumvention violates 17 U.S.C. 1201(a)(1)(A)[1] unless the copyright owner has authorized the process (as they do with licensed playback devices and software).
And with only narrow exceptions that probably don't apply here, this act of circumvention violates 17 U.S.C. 1201(a)(1)(A)[1] unless the copyright owner has authorized the process (as they do with licensed playback devices and software).
[1] https://www.law.cornell.edu/uscode/text/17/1201