Perhaps woken by news of its next premier first-party title already looking really impressive on emulators, Nintendo has moved to take down key tools for emulating and unlocking Switch consoles, including one that lets Switch owners grab keys from their own device.

Simon Aarons maintained a forked repository of Lockpick, a tool (along with Lockpick_RCM) that grabbed the encryption keys from a Nintendo Switch and allowed it to run officially licensed games. Aarons tweeted on Thursday night that Nintendo had issued DMCA takedown requests to GitHub, asking Lockpick, Lockpick_RCM, and nearly 80 forks and derivations to be taken down under section 1201 of the Digital Millennium Copyright Act, which largely makes illegal the circumvention of technological protection measures that safeguard copyrighted material.

Nintendo's takedown request (RTF file) notes that the Switch contains "multiple technological protection measures" that allow the Switch to play only "legitimate Nintendo video game files." Lockpick tools, combined with a modified Switch, let users grab the cryptographic keys from their own Switch and use them on "systems without Nintendo's Console TPMs" to play "pirated versions of Nintendo's copyright-protected game software." GitHub typically allows repositories with DMCA strikes filed against them to remain open while their maintainers argue their case.

Still, it was an effective move. Seeing Nintendo's move on Lockpick, a popular Switch emulator on Android, Skyline, called it quits over the weekend, at least as a public-facing tool you can easily download to your phone. In a Discord post [Edit, 5pm Eastern: Previously described as removed, but now linked], developer "Mark" wrote that "the risks associated with a potential legal case are too high for us to ignore, and we cannot continue knowing that we may be in violation of copyright law."

Prior to Nintendo's DMCA request, Skyline's team had believed that using keys from your own Switch console, to emulate games you legally purchased, was legal. Skyline remains as an open source project, though the core team will not update or otherwise work on it as of Sunday. Other popular Switch emulators for PC, Yuzu, and Ryujinx, remain online, with the Ryujinx team issuing a statement on their Discord that they would not be shutting down, according to news reports.

Lockpick, which remains up as of this writing, has been in development since early 2019. Nintendo's sudden interest in ensuring that people can't rip keys from their Switch or emulate Switch games regardless of provenance likely stems from this week's May 12 launch of The Legend of Zelda: Tears of the Kingdom. Physical copies of Tears began circulating shortly before May 1, leading to the game being dumped, pirated, played, and streamed, although usually for only moments before Nintendo moved to shut down Discord servers and Twitch streams.

Nintendo has been fighting uses of its hardware beyond anything it intended for nearly its entire life, at least as a video game company. The DS, 3DS, Wii, and even the Game & Watch novelty release have all seen hacking and homebrew scenes. The Switch, in particular, has seen Nintendo work hard to avoid widespread piracy, setting up online blockers for pirates, releasing new hack-resistant hardware, targeting online mod retailers, issuing ISP-level blocks, and, most recently, following through on criminal prosecution that will leave one hack-team member likely paying the company for the rest of his life.

Every time Nintendo clamps down on the tools used to enable piracy, it also disrupts the ecosystems that produce Linux installations, homebrew games and tools, and emulators for legally purchased games. That said, Tears of the Kingdom is rather easy to find online at the moment, as are exhaustive guides to getting the game running in PC emulation tools. The cat seems entirely out of the bag, but this cat also requires hours of effort to get running smoothly on even the most upgraded PC and requires lots of downloads from sites that push ad blockers to their limits.

Most people who want to really play and enjoy Tears will do so with a Switch and a purchase. Nintendo will mostly succeed at making any other approaches harder to pull off.