Good luck, especially if they try to ban people from ripping their CDs to FLAC as well, like, how would you even find out if someone is doing that, for instance?

Unless you somehow force a backdoor into rippers like Exact Audio Copy, CUERipper, or Whipper, the latter two being OSS, you can’t.

Even SCMS never phoned home to anyone simply because the capability to do that didn’t exist yet when that copy protection scheme was first implemented, and it only applied to dubbing a CD over to DAT, MD, or DCC over S/PDIF on consumer gear.