There is a special law - the DMCA - saying you can't break digital locks that were placed in the name of copyright, ever. Even telling someone how to break a lock is illegal. Even learning how to break a lock is illegal. Even probing at a lock in ways that might reveal how to break it is illegal.
There's a reason that people say corporations own us, or corporations own the law. In some cases, acts that might result in lowered profits are punished worse than murder.
The DMCA does not apply in Canada, so I'm not sure if telling someone how to break the lock is illegal.
Being a Canadian, I really should look this up. That being said, I try to avoid situations where I would want to break a digital lock. There are plenty of alternatives encumbered media, provided that you don't have your heart set on a particular product. For example, many publishers offer unencumbered ebooks. Library books do have DRM, but it is pretty much a given that some sort of access control is needed since the books are on loan.
In practice, though, the real source of this stuff is the WIPO Copyright Treaty, wherein 116 countries around the world agreed to adopt similar laws on this topic. Those "one-world government" conspiracy theorists have a point!
The typical area where this comes up is 17 USC 1201(a)(2); "No person shall manufacture, import, offer to the public, provide, or otherwise traffic in any technology, product, service, device, component, or part thereof, that" [breaks DRM]. "Otherwise traffic" is a big universe of actions, as is "offer to the public."
The courts that handled the DeCSS cases (code that broke DVD encryption) allowed that code like DeCSS was speech protected by the First Amendment, but basically ruled that the functional aspect of the code meant it gets lesser protection. Posting the code, but even just linking to somewhere else it could be found, were both found to violate the DMCA, and that restriction was found to be permitted by the First Amendment.
Exact source is a bit convoluted, because most US law is convoluted, but is covered in multiple subsections of section 1201 of Public Law 105–304 (the technical name for DMCA). There are exceptions for things like making things interoperable and security research (kinda), but beyond that simply glancing at one of these locks can be a violation of DMCA. Sadly the document is excessivly long (60 pages plus references to other laws), and the available source PDF is so poorly formatted as to be nearly impossible to follow (nothing is aligned correctly, and subsections regularly form a very confusing pattern)
There's a reason that people say corporations own us, or corporations own the law. In some cases, acts that might result in lowered profits are punished worse than murder.