[wxw]

The actual bill in question: https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml...

It seems more precise to say that 3D printers sold/transferred in California would need built-in anti-firearm-printing controls?

I don't see how this directly bans students/teachers/businesses from owning 3d printers, which is what the title seems to say.

[SpicyLemonZest]

It does not. The gun lobby routinely lies about California regulations to try and get their way. They're on year 13 of boycotting the California handgun market, for example; new handgun models in the state are required to adopt microstamping technology, but firearms manufacturers are ideologically opposed to this technology, so they falsely claim that it doesn't exist.