In 2000, federal and state legislation was introduced that would require safety locks on firearms as well as ban the importation of high-capacity ammunition magazines. Though laws were passed that made it a crime to buy guns for criminals and minors, there was considerable controversy over legislation pertaining to background checks at gun shows. There was concern in the gun lobby over restrictions on Second Amendment rights in the United States. Frank Lautenberg introduced a proposal to close the gun show loophole in federal law. It was passed in the Senate, but did not pass in the House.