California ghost-gun bill wants 3D printers to play cop, EFF says
- Reference: 1776187536
- News link: https://www.theregister.co.uk/2026/04/14/eff_california_3dprinted_firearms/
- Source link:
Advocates at the Electronic Frontier Foundation (EFF) say that such legislation could empower manufacturers to introduce restrictive policies affecting consumer choice. It could lead to widespread surveillance of users' printing activity, which they fear could lead to copyright lawsuits, if that data were shared with other companies looking to protect against 3D-printed spare parts, for example.
The bill in question is [1]AB 2047 , the scope of which, on paper, appears strict. The primary goal is clear and simple: to require 3D printer manufacturers to use a state-certified algorithm that checks digital design files for firearm components and blocks print jobs that would produce prohibited parts.
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Federal law does not impose a blanket ban on making firearms for personal use, though ghost guns are subject to various federal and state restrictions, and the practice remains controversial nationwide.
[3]
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Gun crime rates in the US far outweigh those in all other developed countries, so introducing legislation to curb the easy manufacture of untraceable firearms will be seen as a positive initiative to many, particularly in regions where guns are more strictly regulated.
However, Cliff Braun and Rory Mir, who respectively work in policy and tech community engagement at the EFF, claim that [5]the proposals in California are technically infeasible and in practice will lead to consumer surveillance.
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In a series of blog posts published this month, the pair argued that print-blocking technology - proposals for which have also [7]surfaced in states including New York and Washington - cannot work for a range of technical reasons.
They argued that because 3D printers and other types of computer numerical control (CNC) machines are fairly simple, with much of their brains coming from the computer-aided manufacturing (CAM) software – or slicer software – to which they are linked, the bill would establish legal and illegal software. Proprietary software will likely become the de facto option, leaving open source alternatives to rot.
"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," [8]wrote Braun earlier this month.
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"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."
Braun also argued that it would be trivial for anyone who uses 3D printers to make small tweaks to either the visual models of firearms parts, or the machine instructions (G-code) generated from those models, to evade detection.
Mir further argued that the bill offers no guardrails to keep this "constantly expanding blacklist" limited to firearm-related designs.
In his view, there is a clear risk that this approach will creep into other forms of alleged unlawful activity, such as copyright infringement.
[10]Ghost gun legislation casts shadow over 3D printing
[11]Leading 3D printing site bans firearm files, but home gun makers have better options
[12]Meanwhile, in Japan, train stations are being 3D-printed in an afternoon
[13]A look under the hood of the 3D-printed, Raspberry Pi powered 'suicide pod'
"This could look like Nintendo blocking a Pikachu toy, [14]John Deere blocking a replacement part, or even patent trolls forcing the hand of hardware companies," wrote Mir. "Repressive regimes, here or abroad, could likewise block the printing of 'extreme' and 'obscene' symbols, or tools of resistance like popular [15]anti-ICE community whistles."
Braun and Mir have a list of other arguments against the bill. They say the algorithms are more than likely to lead to false positives, which will prevent good-faith users from using their hardware.
Many 3D printer owners also have no interest in printing firearm components. Most simply want the freedom to print trinkets and spare parts while others use them to print various items and sell them as an income stream.
That said, Gun Owners of California also [16]opposes the bill , arguing that it does not target criminals, only innocent consumers and businesses.
"Californians deserve policies that focus on criminal misuse – not sweeping mandates that expand bureaucracy and restrict lawful activity," it wrote in a response to the bill's introduction in February.
Addressing the community behind [17]3D printer manufacturer and slicer provider Prusa Research, community manager Tommy Muszynski said the company is keeping a close eye on developments.
"At Prusa, safety is obviously the highest priority," he [18]said in a comment on Reddit. "We want everyone to have a safe experience in this hobby, but at the same time, we have always been firm believers in the 'right to repair' and the right for you to use the machine you bought however you see fit.
"We've built our community on open source principles and the idea that your printer is a tool for your own creativity, not a device that should be locked down or surveilled." ®
Get our [19]Tech Resources
[1] https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill_id=202520260AB2047
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/legal&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2ad65A1L8mRhzNef3MtD9dAAAAcg&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/legal&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44ad65A1L8mRhzNef3MtD9dAAAAcg&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/legal&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33ad65A1L8mRhzNef3MtD9dAAAAcg&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[5] https://www.eff.org/deeplinks/2026/04/dangers-californias-legislation-censor-3d-printing
[6] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/legal&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44ad65A1L8mRhzNef3MtD9dAAAAcg&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[7] https://www.theregister.com/2026/02/05/ghost_gun_legislation_3d_printing/
[8] https://www.eff.org/deeplinks/2026/04/print-blocking-wont-work-permission-print-part-2
[9] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/legal&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33ad65A1L8mRhzNef3MtD9dAAAAcg&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[10] https://www.theregister.com/2026/02/05/ghost_gun_legislation_3d_printing/
[11] https://www.theregister.com/2025/07/23/thingiverse_drops_3d_gun_designs/
[12] https://www.theregister.com/2025/03/28/japan_3d_printing_railway/
[13] https://www.theregister.com/2024/09/25/3d_printed_raspberry_pi_suicide_pod/
[14] https://www.theregister.com/2026/04/09/john_deere_repair_settlement/
[15] https://www.theregister.com/2026/01/09/hackers_fight_back_against_ice/
[16] https://gunownersca.com/take-action-ab-2047-bauer-kahan/
[17] https://www.theregister.com/2025/07/23/thingiverse_drops_3d_gun_designs/
[18] https://www.reddit.com/r/prusa3d/comments/1r9jjza/comment/o6dvb1i/
[19] https://whitepapers.theregister.com/
Trivial for crackers to bypass
The warez scene has spent decades churning out activation cracks, no-CD patches, etc.
Skilled software crackers can do this in days, sometimes hours, against software companies which have enormous budgets and huge incentives to stop software piracy. Pretty much every attempt to stop offline software cracking has failed.
Likewise, hardware giants like Apple can't stop jailbreaks despite budgets for integrated software and hardware ecosystems that exceed 3D printer manufacturers by many orders of magnitude.
3D printer manufacturers have no incentive to make their software difficult to crack, not that it would help anyway.
This stupid idea is doomed to failure.
Huge risk to inventors
Hackers have tremendous incentive to root the backend servers and steal designs for parts, particularly those still under development and not yet released to market.
3D printer manufacturers could face enormous financial liability for a cybersecurity incident which results in the theft of a user's active development project.
Rough on Harbour Freight
Presumably mills and lathes will now all have to be CNC and programmed not to produce gun parts
Why not
Add age verification to 3D printers while they're at it? In the name of safety of course.
Re: Why not
Why start with 3D printers?
You can make weapons with much more primitive tools
Think of the children, ban flint now !
Re: Why not
Saltpeter can be made with urine. We need constant urethral monitoring (from multiple angles) to ensure only the proper authorities are taking the piss.
Gun crime rates in the US
And in Mexico, where most of the narcos guns come from the USA.
Re: Gun crime rates in the US
I guess you got the usual obligatory downvotes (3 at this time). Either that or they are genuinely ignorant.
Why 3D Printers?
3D printers print various types of plastic (ABS, PETG, PC, etc), which all are a pretty bad fit for temperatures and pressures inside a discharging firearm.
So why are we not talking about CNC mills or lathes that in fact are capable of producing working gun parts?
Re: Why 3D Printers?
3D printers print various types of plastic (ABS, PETG, PC, etc), which all are a pretty bad fit for temperatures and pressures inside a discharging firearm.
Gluck etc helped pioneer polymer framed perforators and political panic followed with ghost guns that could evade metal detection. Or not, given metallic ammuniton, barrels etc. Which could also be plastic, providing you didn't want to fire them often. But sintered metal machines also exist to print metal parts.
So why are we not talking about CNC mills or lathes that in fact are capable of producing working gun parts?
They'll be next. Then the likes of Nintendo & Games Workship. No printing guns, certainly no printing space.. soldiers carrying bolters. Or furniture to make your 'assault' rifle look like a bolter, and furniture isn't an NFA item, at least until IKEA jump into the CDP file game. Once the genie's out of the bottle, there'll be the inevitable scope creep. Charles Stross also wrote about this in Rule 34(?) years ago.
But a pointless bit of gesture politics given there's existing law against supplying NFA items, complete with heavy penalties. Stopping people 3D-printing stuff won't stop people making zip guns.
Re: Why 3D Printers?
"3D printers print various types of plastic (ABS, PETG, PC, etc), which all are a pretty bad fit for temperatures and pressures inside a discharging firearm."
There's a lot more to 3D printing than just filament printers. 3D printed metal parts are very common these day and they aren't useful for making the parts that undergo lots of mechanical and temperature extremes. There are a few designs for small caliber one shot weapons but, they can pose as much risk to the shooter as their intended victim.
Well durrr...
These open source files and 3D printers are clearly the reason the USA has such a high gun crime rate, just look at say Europe and see the huge levels of gun crime also caused by these ghost guns.
Oh hold on....
What are firearms?
A firearm, legally, is just the receiver. Triggers, barrels, hand grips, hammers, firing pins, and everything else is just stuff.
Using Glock as an example, could someone 3D print the polymer receiver and then buy the commodity items to complete the weapon? Sure, I'll bet there are plans out there already to 3D print a Glock receiver.
Now go lookup how Glocks are made and the specialized polymer used in their frames, and compare. No way would I drop the hammer on a 3D printed Glock look-a-like!
Might as well ask me to hold a live hand grenade with the pin pulled! It might go 'bang' a few times, but that 3D printed plastic will never be as strong as the real thing. It will eventually perform an 'unplanned rapid disassembly' in front of my face.
This is a law looking for a problem to solve.
it will probably work as well as the law that was supposed to stop you being able to use a scanner to scan a bank note. Sure your HP and Canon included bloatware software might not let you but loads of 3rd party software will absolutely let you.
Rotsa ruk Shaggy
When printing a bank note, it has to be spot on. When printing parts for a firearm, there is all sorts of room for design choices.
Any checking algorithm will need to be secret which would mean that there would be no way to tell why your non-firearm part is being blocked from printing. Commercial printing companies will have to locate in states that don't have such restrictions as false positives will be very costly. Any implementation will need an internet connection as the database of reference designs could be massive. Who would maintain the code and database for this? The Ministry of Naughty Print Files with the head Czar ensconced in a gilded office building in downtown San Francisco?
The issue is that judges and prosecutors have gone rotten soft. The rapper Offset who was praised for being brave enough to appear for a performance less than a week after being shot is a convicted felon. I learned that while binging badgecam videos where he had been stopped for dark tinting on his pimped Corvette and the cops spotted 3 loaded handguns in the car and promptly arrested him for "felon in possession". This was before being shot. There wasn't backstory on this in the video and I can't be bothered, but a felony conviction and out driving an illegally modified car and tagged for what should be a major offense should mean a drastic lifestyle change. There's a lot of cherry picking on those video compilations, but there seems to be endless fodder to find people arrested that have rap sheets so long that inkjet ink is being bulk purchased to print them out.
The application of a serial number doesn't make tracking a firearm possible other than from an accounting standpoint. It's no RFID and a large portion of firearms used in crime are stolen. Somebody legit is followed home from the practice range and being a good citizen, locks their guns in their safe. A really cheap safe that's not that hard to break open and not hard to find in a house. If the safe is small enough, they just steal the whole thing and worry about cracking it open later. The owner (assuming legal ownership) will report the theft. The serial number fails to send out a beacon to satellites in orbit and the only way the weapon might be found again is if it is recovered from a crime scene. The really stupid perps will keep the gun after committing a crime with it, but they were going to get popped at some point down the road anyway being that mental. The videos they've posted on social media bragging about the crime while displaying the weapon, if allowed in evidence, will seal their fate, for the next 6 months.
From the people who brought you 80% lowers
80% printers: a 3D printer with just a bootloader and instructions for California residents to please load the ridiculous rights destroying firmware and absolutely not the unrestricted open source firmware that lets you use your personal property as you see fit.
Hopefully this nonsense goes the way of the infamous Bambu 'security' update that froze out third party slicers until they caved and allowed people to unlock their machines.