I strongly believe we should use the phrase "DRM restricted", not "DRM protected".
"Protected" is what the publishing industry wants us to say, because protection sounds like a good thing. But what are they "protected" against? They're protected against us being able to use them, which is what caused Linda to lose the use of all of her books. We need to be careful not to perpetuate the publishers' spin and propaganda, and one way to do that is to not allow them to choose our vocabulary for us.
It's a small thing, but so is a sequoia seed.