The Department of Homeland Security (DHS) issued a May 21 bulletin that said it may be "impossible" to stop 3D-printed guns from being created.
The bulletin from the DHS' Joint Regional Intelligence Center was sent to local and federal law enforcement agencies and warned them about "public safety risks" that 3D-printed guns present.
The DHS explained how 3D-printed guns are created by downloading blueprints off the web and using high-end computers to mold the gun from melted plastic.
According to FoxNews.com, the bulletin states: "Significant advances in three-dimensional (3D) printing capabilities, availability of free digital 3D printer files for firearms components, and difficulty regulating file sharing may present public safety risks from unqualified gun seekers who obtain or manufacture 3D printed guns."
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The bulletin mentions "Defense Distributed," which placed the blueprints for 3D-printed guns online for almost a week. Even though the U.S. government ordered them taken down, about 100,000 copies for the "The Liberator" gun were downloaded. Now, bit torrent sites are offering the blueprints for downloading.
The bulletin also says: "Proposed legislation to ban 3D printing of weapons may deter, but cannot completely prevent their production. Even if the practice is prohibited by new legislation, online distribution of these digital files will be as difficult to control as any other illegally traded music, movie or software files."
"This is a serious threat," an unidentified law enforcement source told FoxNews.com. "These could defeat magnetometers. The only security procedure to catch [3D-printed guns] is a pat down. Is America ready for pat-downs at every event?"