California AB 2047 — Mandatory 3D Printer Censorware

California's AB 2047 is the most controversial piece of 3D printing legislation ever proposed in the United States — and it affects every 3D printer owner, not just those interested in firearms.

The bill would require manufacturers to install "censorware" — software that algorithmically blocks certain print jobs — on every 3D printer sold in California. More alarming, it would make it a criminal misdemeanor for users to disable, deactivate, or circumvent these algorithms.

In practical terms, this would criminalize the use of open-source firmware like Klipper and Marlin, which power the majority of hobbyist 3D printers. It would also enable printer manufacturers to lock users into purchasing first-party filament and parts — similar to how 2D printer manufacturers have used DRM to force users to buy expensive branded ink cartridges.

The Electronic Frontier Foundation (EFF) published a strongly-worded opposition piece in April 2026, calling the bill "a gift to the biggest 3D printer manufacturers" and warning that it would enable planned obsolescence, platform lock-in, and surveillance of what users print.

The bill is currently in the California legislature. It has not passed.