In many countries around the globe this is absolutely not a crime, copying content that you own is perfectly legal and not even a grey area.

True in many parts of the world. U.S. copyright law makes no exception for copying content you own, though I do agree it may be hard for media companies to prosecute so you'll probably get away with it. The Betamax Supreme Court case was won -- 5-4 -- because the court found a single, very narrow, noninfringing use for a VCR: recording a television program that will air only once and never again after that single airing, and you cannot be around to view said television program at its scheduled time, and you intend to destroy the recording after viewing it once. The ruling does NOT cover recording off the TV willy-nilly, or copying things you own; there is a dicta in Justice Blackmun's dissent stating these things to be explicitly illegal.

But I'm not talking about doing the copying itself. I'm talking about circumventing DRM which is a separate offense from copyright infringement. That is illegal in the USA, with certain specific, narrow exceptions, whether you use such circumvention to infringe copyright or not. Trafficking in circumvention devices, including publishing or downloading firmware that disables access protection measures, is illegal full stop.

(Remember DeCSS? Yeah, hosting that is still a federal crime, irrespective of what you or your audience intends to do with it. The irony is, that means the Feds have every right to take Eric S. Raymond's guns away and bar him from owning a gun for life: http://www.catb.org/esr/netfreedom/)

I'm not sure that the modded firmware even includes the actual low-level read routines. Isn't the whole thing split up to load them into the drive's RAM after every power cycle? If that's the case then the modded firmware alone is arguably not a circumvention device, and neither is the drive once it's powered down. :P

LibreDrive disables the "policing", i.e., the software that makes the drive refuse to read due to a wrong region code, revoked key, etc. This counts as an "effective technological measure" separate from any decryption, etc. the drive performs and LibreDrive is thus likely a circumvention device under the DMCA. Publishing it would therefore be a felony, punishable by up to five years in federal prison, in addition to civil penalties.

Agreed but LibreDrive is the system as a whole (before decryption, sure). I was curious about the persistent component of that system, the modded firmware.

I understand, and I assume you're probably right. What I'm saying is that it's ok to commit this crime. You're not harming anyone, and in the particular scenario we're talking about, there's no chance that you'll face any consequences.