The usage is much more appropriate to RMS's backronym "digital restrictions management".
Content Restriction Access Management would cover all content, including liquid ink.
Though you can argue that "digital" in this case is referring to the chip and reader. These are infact digital components restricting access to liquid.
Maybe Consumer Restricted Access Pattern.
In essence those are monopolistic and consumer hostile practices.
Most of what DRM does on a video isn't enforcing legal copyright either.
> And the ink being controlled is not even solid, let alone digital. It's merely a computerized lock on a physical item.
Does 'digital' apply to the rights or to the management?
The copyright on a (printed) book doesn't let the publisher dictate where and how the book can be read. As long as you're not making copies or derivative works or putting on a public performance you can consume it however you wish. Even on those cases there are exceptions for fair use, e.g. parody. The same applies to DRM-free audiovisual recordings. Anyone can make a player for VHS tapes or DRM-free DVDs without running afoul of copyright, but the same is not true once DRM is involved thanks to the anti-circumvention clauses of the DMCA, and that gives publishers far more power to dictate how copyrighted (or even formerly copyrighted) works can be used than they would have under copyright alone.
In many legal systems you have a definition of fair use that allows you to do more with the content that you purchased than what producers would like.
For example - you are free to share it with family and close friends, play on as many devices and on whatever software you wish, and share wildly short clips. DRM prevents all that.
Thus, it is common in hacker circles to consider DRM as an abbreviation for Digital Restrictions Management.