> In most (all?) jurisdictions copyright infringement is a civil matter

This is just absolutely 100% factually inaccurate. There are huge swaths of legislation specifically to spell out the fact that this is not the case. Please refer to the other sub-threads, particularly the information about arrests being made!

> Modifying (Removing DRM on) a piece of software that you yourself have bought is perfectly legal.

Not likely. At least not for any practical use cases.

The point of removing "rights management" would typically be to grant yourself rights that the copyright holder did not wish to grant you. IANAL, however if you were to remove DRM, but then continue to use the software in a manner that is in line with what the rights-holder intended, then you may be okay. Although, the laws themselves indicate that facilitating removal of DRM is in itself illegal, so I wouldn't count on it.

If you were to distribute any tooling, or even technical information about the removal of the DRM, then you're in clear violation. In fact, the stringency of these laws is how the case in the aforementioned Gizmodo article even came to be. Some rights-holders believed that simply mentioning the existence of DRM removal software was a violation of these laws. Fortunately, the courts ruled otherwise, but that's a far cry from publishing technical information explaining how to remove the DRM itself.

From the WIPO Copyright Treaty:

> Article 12
Obligations concerning Rights Management Information

(1) Contracting Parties shall provide adequate and effective legal remedies against any person knowingly performing any of the following acts knowing, or with respect to civil remedies having reasonable grounds to know, that it will induce, enable, facilitate or conceal an infringement of any right covered by this Treaty or the Berne Convention:

(i) to remove or alter any electronic rights management information without authority;

(ii) to distribute, import for distribution, broadcast or communicate to the public, without authority, works or copies of works knowing that electronic rights management information has been removed or altered without authority.

(2) As used in this Article, “rights management information” means information which identifies the work, the author of the work, the owner of any right in the work, or information about the terms and conditions of use of the work, and any numbers or codes that represent such information, when any of these items of information is attached to a copy of a work or appears in connection with the communication of a work to the public.

The WIPO Copyright Treaty has been implemented all around the globe. In the US these laws are largely incorporated as part of the DMCA. The DMCA has provisions for fair use and the right to repair exemptions. However, these exemptions aren't even part of the legislation. Instead, every three years the copyright office reviews the exemptions, adding, removing and extending exemptions as they see fit. What's legal in the US now, may not be in three years time.

Article 10 of WIPO Copyright Treaty allows "Contracting Parties" (signatories of the treaty) to incorporate certain exemptions in their legislation. However, it's not at all clear that this section even applies to Article 12. The US have provided exemptions, "because they can". Other countries around the globe are not so lucky.

Take Australia for example, the WIPO Copyright Treaty was simply implemented as amendments to Australia's Copyright Act in 2000. Australia has no exemptions, nor any special processes to introduce them.