The Library of Congress has ruled it is legal to hack some old games and consoles in specific circumstances to keep them running.

The latest set of rulings on DMCA exemptions also allow for limited hacking of the software that runs “smart cars.”

The exemptions are part of a regular review by the Library of Congress on the Digital Millennium Copyright Act. That’s the law which states a general principle that tinkering with any electronic system designed to protect copyright is unlawful, even if you don’t actually go on to breach copyright itself. The reviews are designed to keep up with changes in technology and give exemptions where strict enforcement wouldn’t really be in keeping with the spirit of the law.

One new exemption applies to games which have become unplayable because they rely on access to remote servers which have now been switched off by the developers. The exemption says you can now lawfully hack such games to keep them running, including modifying consoles if needed.

However, the exemption doesn’t apply in cases where the server shutdown merely makes multiplayer modes unusable but the game can still be played offline.

The exemption for smart cars covers two specific uses: security researchers looking for bugs, and people modifying the software to carry out repairs. It doesn’t cover extracting code or passing it on for profit.

Two existing exemptions have been extended. While smartphone jailbreaking was already permitted, jailbreaking is now also legal on many other mobile devices such as tablets and wearable tech.

There’s also a tweak to an exemption on reproducing video content while making a “remix” for non-commercial uses. That now specifically applies to ripping content from DVD, Blu-Rays and streaming services.