I think you are incorrect Quantum. The law (in the US) is that devices that are primarily intended to circumvent protection measures, or are marketed as such are illegal to sell. It's a crappy law (for the stealers).
https://en.wikipedia.org/wiki/Anti-circumvention
https://www.law.cornell.edu/uscode/text/17/1201
DVDs/CDs on the other hand do not have circumvention / copyright violation as a clear primary purpose albeit a pretty obvious one.
ripping DVDs however and circumvention of any DRM on a DVD even make a backup is in fact a
violation of US law (this is especially crappy). So making a backup of your DVD may not be illegal, but the fact that you are circumventing encryption in the process IS illegal. That said, some courts have waffled on this a little bit.