Legislators can pass bills for things like universal background checks and the “no fly, no buy” rule, but those policies target if someone can purchase a gun. Things become a lot more complicated when citizens can make their own guns at home—and that’s becoming a significant issue as technology advances.

Cody Wilson is the founder of Defense Distributed, a gun advocacy organization that shares code for 3-D-printing guns at home. He said his organization has shared “almost millions” of files for printing guns at home, and has sold thousands of milling machines that can make the lower receiver of an AR-15. The guns these machines make are called “Ghost Guns” because they’re essentially untraceable.

The AR-15 has been the subject of much debate, as many want to ban it after it was used in several mass shootings. However, Wilson thinks the debate around the AR-15 is “ridiculous.”

“When we fixate on things like the AR, most of that’s done for partisan reasons that avoid the true root of ‘gun crime.’ [Gun crime] is dominantly produced by the hand gun, and dominantly conducted in these urban environments that have all kinds of variables—gang violence, endemic poverty,” Wilson told The Daily Beast.

Wilson said politicians are focusing on the AR-15 because it’s an easy target, and they’re trying to get publicity during the election season. He is staunchly against the bill that would deny gun-purchasing rights to people on a terrorist watch list.

“I have nothing but contempt for people that would support secret list culture and the Stasi environment that that creates,” Wilson said. He also said expanding background checks might be useless because of people like him.

“Give all the background checks that you want. My company is built around evading that entire program,” he said.

Thousands of amateur gun manufacturers could be operating independently around the country without anyone knowing. As these untraceable guns spread throughout the country, the identities of their creators get completely lost.

It remains unclear how politicians will get around the issue of people making their own guns at home. Someone with a 3-D printer or a milling machine can make a gun at home without being connected to a network that might detect what they’re doing.

“You’d basically have to pass a law saying it’s illegal to make something without a license, and you could probably get that done, but that’s really a tectonic shift in gun politics—a much heavier list than saying, ‘We’re going to add X and Y to the background check requirements,’” Wilson said. He said that since 3-D printers are general-purpose devices, it would be difficult to ban making a specific item with them. He also said that the First Amendment protects sharing files, like the files his company shares for making guns.

The city of Philadelphia made headlines in 2013 when it banned 3-D-printed guns. Trying to do such a thing on a much larger scale might prove to be difficult.

“[3D printing guns] certainly adds a layer of complexity to gun control that we haven’t seen before, and it’s likely to undermine many of our current gun laws,” Adam Winkler, a law professor at UCLA and Second Amendment expert, told The Daily Beast.

“You could prohibit the manufacture of these firearms… nonetheless, the technology will still exist, and as long as the technology exists, any legislation becomes difficult to manage,” Winkler said.

Winkler said you could control the 3-D-printing of guns in the short term by requiring people to be licensed before they purchase a 3-D printer, but the technology will become cheaper and more available as time goes on.

Rep. Steve Israel (D-NY) has repeatedly tried to introduce legislation that would prevent people from owning or manufacturing plastic 3-D-printed guns that can pass metal detectors. So far, he hasn’t been successful.

“This is about updating our laws to keep up with changing technology,” Rep. Israel told The Daily Beast. “Law enforcement needs to be able to stop a lone wolf who wants to build a plastic, fully-functioning weapon in his home and then bring it onto a plane or into a secure environment to hurt innocent Americans.”

When someone can make their own gun in their free time, passing laws that dictate who can purchase guns at the local store might be futile.