When Paweł Jarczak got a private Reddit message from Bambu Lab asking him to delete his code, the company probably didn’t expect what came next. Now the 3D printing community has rallied around Jarczak, raising funds for what could become a landmark fight over open-source licensing and the AGPL.

The dispute centers on a piece of software Jarczak wrote that lets people control their Bambu Lab 3D printers remotely without using Bambu’s own software. Bambu didn’t like that. According to The Verge’s reporting, the company sent Jarczak a private message demanding he take down his code. His response, now famous in the 3D printing community, was just two words: “Fuck you.”

That’s where things got legal.

What Bambu claims

The technical details matter here. Jarczak’s code apparently interfaces with Bambu’s printers, and Bambu’s firmware uses code licensed under the AGPL, the Affero General Public License. The AGPL is the strictest of the major open-source licenses. It requires anyone who modifies AGPL code and runs it on a server to release their modifications under the same license.

Here’s the thing: if Bambu really is using AGPL code in its firmware but hasn’t released its own source code, Bambu might be the one violating the license, not Jarczak. That’s the argument the community is making, and it’s not a crazy one.

Bambu has also allegedly threatened DMCA takedowns. The DMCA, the Digital Millennium Copyright Act, makes it illegal to circumvent technological protection measures. If Bambu argues that Jarczak’s code circumvents copy protection or security features in their printers, they could file a DMCA notice with GitHub or other platforms hosting the code.

But DMCA claims are tricky. The code has to actually circumvent a protection measure, not just provide an alternative way to control hardware you own. Courts have been skeptical of DMCA claims that try to prevent interoperability or lock customers into proprietary software.

Why this matters

This isn’t just about one developer and one company. It’s about whether 3D printer manufacturers can use open-source code to build their products, then turn around and threaten legal action against users who write their own software to control the hardware they bought.

The right-to-repair movement has fought similar battles. Massachusetts passed a law requiring car manufacturers to use open data formats. The FTC has pushed back against companies that use software locks to prevent independent repair. The legal principle is straightforward: if you buy hardware, you should be able to run whatever software you want on it.

The AGPL angle makes this more interesting. If Bambu really is using AGPL-licensed code without complying with the license terms, Jarczak isn’t just a defendant. He’s a potential plaintiff, or at least evidence in someone else’s case. The Software Freedom Conservancy and the Free Software Foundation have both brought AGPL enforcement actions before. They tend to win.

What happens next

The 3D printing community is funding Jarczak’s legal defense. That’s significant. Most individual developers fold when a company threatens legal action because litigation is expensive. If Jarczak has the resources to fight back, Bambu has to actually prove its case rather than just sending scary letters.

If this goes to court, expect fights over:

• Whether Bambu’s firmware actually uses AGPL code, and if so, whether Bambu has complied with the license
• Whether Jarczak’s code circumvents any protection measures under the DMCA
• Whether users have the right to run third-party software on hardware they own
• Whether Bambu’s private Reddit message and subsequent threats constitute copyright misuse or anticompetitive conduct

Bambu could also just back down. Sometimes companies send legal threats without thinking through whether they can actually win. If Bambu’s lawyers look at this closely and realize the AGPL issue cuts against them, the smart move is to drop it.

But if Bambu pushes forward, this could set precedent for the entire open-source hardware movement. 3D printers, home automation devices, routers, and other consumer hardware increasingly run on open-source code. If manufacturers can use that code but prevent users from modifying or extending it, the whole point of open source collapses.

The 3D printing community picked the right fight. Now we’ll see if Bambu wants to finish it.