alt Hacker NewsKillers are going to kill. Guns don't democratize it, just makes it easier. Maybe at best YOU could kill one or two:
https://www.cnn.com/2024/11/16/china/china-stabbing-yixing-c... (8 stabbed to death) https://en.wikipedia.org/wiki/Chenpeng_Village_Primary_Schoo... (1 killed, 24 injured)
So they should stop you from 3d-printing knives too.
Successful mass murders with a knife are fairly rare. Killing people that way is physically difficult, and it's relatively easy to just tackle you.
Traditionally, arson was the means of mass killing, as it didn't have either problem. That's gotten much more difficult due to fire safety.