The rules are part of newly adopted exemptions to the Digital Millennium Copyright Act (DMCA), which prohibits circumventing digital rights management (DRM) protections used to safeguard copyrighted works.
Every three years the Copyright Office makes a ruling on petitions for new exemptions or the cancellation of existing ones.
The new ruling, which comes into effect on October 28, affects the legality of owners and professional repairers bypassing access controls on devices for specific purposes, for example, for repairs, jailbreaking, unlocking a device from a carrier's network, accessibility, and education.
The ruling covers an array of devices, including smartphones, tablets, mobile hotspots, wearables, smart TVs, vehicles -- including cars and tractors, as well as smart home appliances like refrigerators, Nest-like devices, and HVAC systems.
Specifically, the rules permit circumvention of access-control features to maintain or repair them.
The Copyright Office explains that the repair-related exemptions cover "computer programs that are contained in and control the functioning of a lawfully acquired motorized land vehicle such as a personal automobile, commercial vehicle or mechanized agricultural vehicle, except for programs accessed through a separate subscription service, when circumvention is a necessary step to allow the diagnosis, repair or lawful modification of a vehicle function."
Security researchers are also exempt from the rules when hacking computer programs, such as electronic voting systems, so long as the activity is carried out in good faith and doesn't break the Computer Fraud and Abuse Act.
Jailbreaking smartphones was already allowed under existing exemptions, and now this situation has been expanded to include smart speakers, like Google Home and Amazon Echo devices.
While the exemptions will be welcomed by right-to-repair advocates, there are still practical limitations and contradictory elements.
As Motherboard notes, companies have made it hard to acquire the tools needed to fix devices and put in obstacles that make it difficult to bypass manufacturer-made restrictions, even if it's now legal to bypass them.
Also, the Copyright Office, part of the Library of Congress, says it can't make an exemption on a rule that makes it illegal for anyone to manufacture or supply tools that could be used to break copyright protection systems.
As Cory Doctorow puts it: "You're allowed to jailbreak your iPhone, but no one is allowed to give you an iPhone jailbreaking tool, and if you make a tool for your own use you can't share it or even tell people how it works."