Ignoring EFF’s warnings about the dangers and impossibility of implementing a new mandate for 3D print surveillance software, the California State Assembly has signed off on legislation to do just that. In the process, legislators amended the bill to make it even more confusing, while failing to address the risks to privacy, speech, and consumer rights. We must renew our call on legislators to drop this bill as it heads to the state senate, and protect the tools of creators in the state.

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What’s changed about the bill?

Since we first wrote about AB  2047, a bill targeting 3D printers for the rare, impractical, and already outlawed practice of manufacturing firearms without a license, it has picked up several amendments. Some are welcome changes, but most have only highlighted the technocratic absurdity of the proposed scheme. Our core concerns—that this mandate censors lawful speech, builds out corporate surveillance, and criminalizes open source experimentation—have not been remedied. 

Removes criminalization of resale

Starting with one silver lining, the current bill includes a carveout for the private resale of devices. The original bill would have made it a criminal offense for an individual to resell 3D printers purchased before this mandated censorship and surveillance software. This is a clear win for the 3D-printing community, but it is unfortunately not enough.

Ineffective carveouts for open source

One of the most dangerous aspects of the bill is that it criminalizes individual users for common practices, like creating and using alternative open source programs with their 3D printer. New amendments provide a carveout for the use of an open source tool, but only if it includes compliant censorship software. The bill burdens open source developers with ambiguous and unrealistic standards for print blocking, and continues to create a chilling effect for open source users.

Removes any actual requirement to work

To reiterate—there is no world where the mandated technology actually works as intended. It will both block lawful use of 3D printers, and allow firearms to be printed by anyone determined to do so. There is no amendment that can change this reality.

Instead, the current bill simply drops the pretense that this mandate is expected to work. The performance standard of algorithms changed from “effectively prevent[ing] a technically skilled user from evading [the algorithm]” to “substantially reduce the likelihood of foreseeable circumvention attempts…” The bill will still require all prints to be surveilled, but instead of testing efficacy against a skilled user, it just plays whack-a-mole with the (literally) infinite number of circumventions that any user can employ. 

Further, the bill now leaves us with an unclear process that relies on non-governmental third parties to define standards, and now relies on manufacturers and resellers to self-police.

Hollywood gets a cut

The bill includes yet another carve out for commercial users. This time for the entertainment industry, which makes extensive use of 3D printers for props and costumes. 

That’s fine for big studios, but it leaves out indie filmmakers, cosplayers, and many other small creators. 

This is simply a defensive edit to limit corporate opposition. There isn’t a clear division in 3D-printing between consumer and commercial tools. These are general purpose tools which might be picked up by a prop department of a big studio, or an artist getting ready for Comic Con. Indeed consumer level products are not only used by amateur artists and engineers developing their skills. Commercial 3D printers, like their traditional 2D equivalents, are frequently used in workplaces, as well as by professionals honing their skills or just trying to get some work done at home. 

Commercial carveouts hands printer manufacturers the ability to sell a more expensive tier of printers, locking-in and up-charging their commercial customers. Some of those customers will choose to buy general retail versions, but that carries its own price: increased risk of IP theft as all printed files are surveilled the same way they are for hobbyists. That means a real risk of businesses leaking any prototypes or new designs to not only the printer manufacturer, but potentially snooping governments and/or the general public through data breaches.

Demand  your senator oppose AB 2047

This updated version of AB 2047 downgrades performance standards and removes oversight while still threatening privacy and choice for users of 3D printers. A printer surveillance system won’t work for its intended purpose, and will only harm law abiding users. 

Act now to demand your senators to vote no on this ineffective and invasive bill.

Take action

Tell CA Senators to stand with creators

California’s bill, A.B. 2047, will not only mandate censorware — software which exists to bluntly block your speech as a user — on all 3D printers; it will also criminalize the use of open-source alternatives. Repeating the mistakes of Digital Rights Management (DRM) technologies won’t make anyone safer. What it will do is hurt innovation in the state and risk a slew of new consumer harms, ranging from surveillance to platform lock-in. California must stand with creators and reject this legislation before it’s too late.

3D printing might evoke images of props from blockbuster films, rapid prototyping, medical research, or even affordable repair parts. Yet for a growing number of legislators, the perceived threat of “ghost guns” is a reason to impose restrictions on all 3D printers. Despite 3D printing of guns already being rare and banned under existing law, California may outright criminalize any user having control over their own device. 

This bill is a gift for the biggest 3D printer manufacturers looking to adopt HP’s approach to 2D printing: criminalize altering your printer’s code, lock users into your own ecosystem, and let enshittification run its course. Even worse, algorithmic print blocking will never work for its intended purpose, but it will threaten consumer choice, free expression, and privacy.

A misstep here can have serious repercussions across the whole 3D printing industry, lead the way for more bad bills, and leave California with an expensive and ineffective bureaucratic mess.

What’s in the California Proposal?

Compared to the Washington and New York laws proposed this year, California’s is the most troubling. It criminalizes open source, reduces consumer choice, and creates a bureaucratic burden.

Criminalizing Open Source and User Control

A.B. 2047 goes further than any other legislation on algorithmic print-blocking by making it a misdemeanor for the owners of these devices to disable, deactivate, or otherwise circumvent these mandated algorithms. Not only does this effectively criminalize use of any third-party, open-source 3D printer firmware, but it also enables print-blocking algorithms to parallel anti-consumer behaviors seen with DRM.

Manufacturers will be able to lock users into first-party tools, parts, and “consumables” (analogous to how 2D printer ink works). They will also be able to mandate purchases through first-party stores, imposing a heavy platform tax. Additionally, manufacturers could force regular upgrade cycles through planned obsolescence by ceasing updates to a printer’s print-blocking system, thereby taking devices out of compliance and making them illegal for consumers to resell. In short, a wide range of anti-consumer practices can be enforced, potentially resulting in criminal charges.

Independent of these deliberate harms manufacturers may inflict, DRM has shown that criminalizing code leads to more barriers to repair, more consumer waste, and far more cybersecurity risks by criminalizing research.

Less Consumer Choice

The bill favors incumbent manufacturers over newer competitors and over the interests of consumers.

Less-established manufacturers will need to dedicate considerable time and resources to implementing the ineffective solutions discussed above, navigating state approval, and potentially paying licensing fees to third-party developers of sham print-blocking software. While these burdens may be absorbed by the biggest producers of this equipment, it considerably raises the barrier to entry on a technology that can otherwise be individually built from scratch with common equipment. The result is clear: fewer options for consumers and more leverage for the biggest producers. 

Retailers will feel this pinch, but the second-hand market will feel it most acutely. Resale is an important property right for people to recoup costs and serves as an important check on inflating prices. But under this bill, such resale risks misdemeanor penalties. 

The bill locks users into a walled garden; it demands manufacturers ensure 3D printers cannot be used with third-party software tools. By creating barriers to the use of popular and need-specific alternatives, this legislation will limit the utility and accessibility of these devices across a broad spectrum of lawful uses.

Bureaucratic Burden 

A.B. 2047’s title 21.1 §3723.633-637 creates a print-blocking bureaucracy, leaning heavily on the California Department of Justice (DOJ). Initially, the DOJ must outline the technical standards for detecting and blocking firearm parts, and later certify print-blocking algorithms and maintain lists of compliant 3D printers. If a printer or software doesn’t make it through this red tape, it will be illegal to sell in the state.

The bill also requires the department to establish a database of banned blueprints that must be blocked by these algorithms. This database and printer list must be continually maintained as new printer models are released and workarounds are discovered, requiring effort from both the DOJ and printer manufacturers. 

For all the cost and burden of creating and maintaining such a database, those efforts will inevitably be outpaced by rapid iterations and workarounds by people breaking existing firearms laws.

Not just California

Once implemented, this infrastructure will be difficult to rein in, causing unintended consequences. The database meant for firearm parts can easily expand to copyright or political speech. Scans meant to be ephemeral can be collected and surveilled. This is cause for concern for everyone, as these levers of control will extend beyond the borders of the Golden State.

While California is at the forefront of print blocking, the impacts will be felt far outside of its borders. Once printer companies have the legal cover to build out anti-competitive and privacy-invasive tools, they will likely be rolled out globally. After all, it is not cost-effective to maintain two forks of software, two inventories of printers, and two distribution channels. Once California has created the infrastructure to censor prints, what else will it be used for?

As we covered in “Print Blocking Won’t Work” these print-blocking efforts are not only doomed to fail, but will render all 3D printer users vulnerable to surveillance either by forcing them into a cloud scanning solution for “on-device” results, or by chaining them to first-party software which must connect to the cloud to regularly update its print blocking system.

This law demands an unfeasible technological solution for something that is already illegal. Not only is this bad legislation with few safeguards, it risks the worst outcomes for grassroots innovation and creativity—both within the state and across the global 3D printing community.

California should reject this legislation before it’s too late, and advocates everywhere should keep an eye out for similar legislation in their states. What happens in California won't just stay in California.

This is the second post in a series on 3D print blocking, for the first entry check out: Print Blocking is Anti-Consumer - Permission to Print Part 1

Legislators across the U.S. are proposing laws to force “print blockers” on 3D printers sold in their states. This mandated censorware is doomed to fail for its intended purpose, but will still manage to hurt the professional and hobbyist communities relying on these tools.

3D printers are commonly used to repair belongings, decorate homes, print figurines, and so much more. It’s not just hobbyists; 3D printers are also used professionally for parts prototyping and fixturing, small-batch manufacturing, and workspace organization. In rare cases, they’ve also been used to print parts needed for firearm assembly.

Many states have already banned manufacturing firearms using computer controlled machine tools, which are called “Computer Numerical Control or CNC machines,” and 3D printers without a license. Recently proposed laws seek to impose technical limitations onto 3D printers (and in some cases, CNC machines) in the hope of enforcing this prohibition.

This is a terrible idea; these mandates will be onerous to implement and will lock printer users into vendor software, impose one-time and ongoing costs on both printer vendors and users, and lay the foundation for a 3D-print censorship platform to be used in other jurisdictions. We dive more into these issues in the first part of this series.

On a pragmatic level, however, these state mandates are just wishful thinking. Below, we dive into how 3D printing works, why these laws won’t deter the printing of firearms, and how regular lawful use will be caught in the proposed dragnet.

How 3D Printers Work

To understand the impact of this proposed legislation, we need to know a bit about how 3D printers work. The most common printers work similarly to a computer-controlled hot glue gun on a motion platform; they follow basic commands to maintain temperature, extrude (push) plastic through a nozzle, and move a platform. These motions together build up layers to make a final “print.” Modern 3D printers often offer more features like Wi-Fi connectivity or camera monitoring, but fundamentally they are very simple machines.

The basic instructions used by most 3D printers are called Geometric Code, or G-Code, which specify very basic motions such as “move from position A to position B while extruding plastic.” The list of commands that will eventually print up a part are transferred to the printer in a text file thousands-to-millions of lines long. The printer dutifully follows these instructions with no overall idea of what it is printing.

While it is possible to write G-Code by hand for either a CNC machine or a 3D printer, the vast majority is generated by computer aided manufacturing (CAM) software, often called a “slicer” in 3D printing since it divides a 3D model into many 2D slices then generates motion instructions. 

This same general process applies to CNC machines which use G-Code instructions to guide a metal removal tool. CNC machines have been included in previous prohibitions on firearm manufacturing and file distribution and are also targeted in some of these bills.

There are other types of 3D printers such as those that print concrete, resin, metal, chocolate and other materials using slightly different methods. All of these would be subject to the proposed requirements regardless of how unlikely doing harm with a gun made out of chocolate would be. 

Simple rectangular 3D model for test fit

Part of a 173490 line long G-Code file produced by slicer for simple rectangular model.

Part of a 173,490 line long G-Code file for a simple rectangular part.

How is Firearm Detection Supposed to Work?

Under these proposed laws, manufacturers of consumer 3D printers must ensure their printers only work with their software, and implement firearm detection algorithms on either the printer itself or in a slicer software. These algorithms must detect firearm files using a maintained database of existing models. Vendors of printers must then verify that printers are on the allow-list maintained by the state before they can offer them for sale.

Owners of printers will be guilty of a crime if they circumvent these intrusive scanning procedures or load alternative software, which they might do because their printer manufacturer ends support. Owners of existing noncompliant 3D printers in regulated states will be unable to resell their printers on the secondary market legally.

What Will Actually Happen?

While the proposed laws allow for scanning to happen on either the printer itself or in the slicer software, the reality is more complicated. 

The computers inside many 3D printers have very limited computational and storage ability; it will be impossible for the printer’s computer to render the G-Code into a 3D model to compare with the database of prohibited files. Thus the only way to achieve this through the machine would be to upload all printer files to a cloud comparison tool, creating new delays, errors, and unacceptable invasions of privacy.

Many vendors will instead choose to permanently link their printers to a specific slicer that implements firearm detection. This requires cryptographic signing of G-Code to ensure only authorized prints are completed, and will lock 3D printer owners into the slicer chosen by their printer vendor.

Regardless of the specifics of their implementation, these algorithms will interfere with 3D printers' ability to print other parts without actually stopping manufacture of guns. It takes very little skill for a user to make slight design tweaks to either a model or G-Code to evade detection. One can also design incomplete or heavily adorned models which can be made functional with some post-print alterations. While this would be pioneered by skilled users—like the ones who designed today’s 3D printed guns—once the design and instructions are out there anyone able to print a gun today will be able to follow suit.  

Firearm part identification features also impose costs onto 3D printer manufacturers, and hence their end consumers. 3D printer manufacturers must develop or license these costly algorithms and continuously maintain and update both the algorithm and the database of firearm models. Older printers that cannot comply will not be able to be resold in states where they are banned, creating additional E-waste.

While those wishing to create guns will still be able to do so, people printing other functional parts will likely be caught up in these algorithms, particularly for things like film props, kids’ toys, or decorative models, which often closely resemble real firearms or firearm components.

What Are The Impacts of These Changes?

Technological restrictions on manufacturing tools’ abilities are harmful for many reasons. EFF is particularly concerned with this regulation locking a 3D printer to proprietary vendor software. Vendors will be able to use this mandate to support only in-house materials, locking users into future purchases. Vendor slicer software is often based on out-of-date, open source software, and forcing users to use that software deprives them of new features or even use of their printer altogether if the vendor goes out of business. At worst, some of these bill will make it a misdemeanor to fix those problems and gain full control of your printer.

File-scanning frameworks required by this regulation will lay the foundation for future privacy and freedom intrusions. This requirement could be co-opted to scan prints for copyright violations and be abused similar to DMCA takedowns, or to suppress models considered obscene by a patchwork of definitions. What if you were unable to print a repair part because the vendor asserted the model was in violation of their trademark? What if your print was considered obscene?

Regardless of your position on current prohibitions on firearms, we should all fight back against this effort to force technological restrictions on 3D printers, and legislators must similarly abandon the idea. These laws impose real costs and potential harms among lawful users, lay the groundwork for future censorship, and simply won’t deter firearm printing.