😂 That is what Ukraine is doing. There's an insane amount of 3d printing for defense going on with hundreds of groups building new drone and other weapons designs every week. Literally: a lot of this stuff is iterated on weekly or biweekly basis, with new designs constantly shipped out. What people don't do is 3d print guns themselves: that's a stupid use of the technology as lots of excellent guns are available on the mass market. Ukraine is not short on guns. If you have money and want to build weapons to kill Russians, Ukraine is the place to do it. The issue is not property rights. No-one is in a position to actually defend themselves against an invading army. That's just not how war at this scale works. Defense by itself simply doesn't work: you can't stop Russia from taking your land by holding your ground. No weapon strong enough exists. You stop Russia from taking your land by working with others to counterattack and respond dynamically. That only works at big scale. Libertarian ideas around war are simply stupid. War does not work that way.