Possibly doing things to reduce straw purchases, which are the #1 means by which people get firearms illegally. Some states have tried limiting the number of firearms that a non dealer can purchase per period of time. Very often the actual buyer goes along with the straw purchaser. I remember an article in The Atlantic years ago about an uncle in Virginia who bought a Cobray (think Mac-10) for his underaged nephew who saved up enough money. It was totally illegal, but he went along with the kid and the dealer saw what the purpose was and still sold it. Another was when Michael Bloomberg was Mayor of NYC, he sent out some people to Virginia to attempt to buy firearms in groups where one buyer was clearly behaving as if the purchaser would transfer it to another person. Virginia responded by making out of state firearms stings illegal under Virginia law unless accompanied by federal or in-state law enforcement.
http://www.washingtonpost.com/wp-dyn/content/article/2007/05/09/AR2007050902573.html
In February, Town & Country Pawn Shop of Roanoke settled with New York and agreed to allow a special judge monitor their firearms sales. But several other dealers, including Bob Moate's Sports Shop in Richmond, are fighting the lawsuit in court.
According to the suit filed in U.S. District Court in Brooklyn, New York police recovered 22 guns between 1994 and 2002, including some used in homicides, that they said were sold by at Bob Moate's. In March 2006, New York sent a man and woman into the store to confirm its suspicion that the store was making illegal gun sales.
"Once the male investigator selected a gun and indicated a desire to purchase it, the female investigator, who had not been part of the discussion, approached the counter to make the purchase," the suit alleges. The woman filled out the required paperwork, but then the man came and paid cash for the gun, the suit says.