The Copy Protection of Audio CDs was intended to negate any attempts to rip or copy the CDs at High Speed. ( Ripping at more than 1 x ). It places intentional errors at strategic locations. these errors are handled by the CD player's error correction, with the CD being read at 1x. However the strtegic location of the errors results in a large cummulative error if the CD is read ( process of ripping) at more than 1x.
I remember the Stereophile CDs were similarly Copy Protected.
I tried to rip one using EAC: Exact Audio Copy ( I did not know it was copy protected).
EAC kept struggling, so I left it over night .....
Next morning I had a Pristine Rip. All copies from the rip are no lomnger "Copy Protected" !