"We Sell Guns! No ID Required. No Background Checks. Criminals and Terrorists Welcome!" That's the slogan on a new 250-foot billboard that a gun control group unveiled on the Massachusetts Turnpike last week, sparking outrage among some gun rights activists.
The National Rifle Association has called the billboard "sensationalistic," saying that the gun control lobby is "way out of line" to use terrorists in a post- 9/11 world to boost their chances of passing gun control laws.
"This billboard is a glaring example of just how low the gun control movement will stoop," a NRA spokesman told ABC News. "It has been standard operating procedure for gun control groups to try and exploit tragedy for political gain," he said, referring to gun control groups' use of school shootings to push for stricter gun laws.
Stop Handgun Violence, a Massachusetts-based non-profit organization, said it erected the billboard to urge Congress to pass a federal law that requires background checks on all firearm transactions, and close the so-called "gun show loophole," which allows customers to purchase guns from "private" sellers without a background check.
"This billboard simply tells the voting public what criminals, terrorists, Congress and the President have known for decades," said Stop Handgun Violence co-founder John Rosenthal.
"If you can't pass a criminal background check, federal law allows you to go to one of the 5,000 gun shows in this country, often on public property like municipal buildings or convention centers, and buy an unlimited number of guns without a background check," said Rosenthal.
Currently 32 states do not require background checks on customers who buy guns from private sellers. Federally licensed gun salesmen, or FFL's, are required to run background checks on their customers in all 50 states and are regulated by the Department of Justice's Bureau of Alcohol, Firearms, Tobacco and Explosives (ATF).
Experts say that because so many guns are purchased at gun shows from private sellers in those 32 states, making them untraceable, it is impossible to statistically link enforced background checks and reduced crime across the board.
"That's just the problem," said Dr. Garen Wintemute, of the University of California at Davis Medical School who studies violence prevention and the American gun market. "These transactions are undocumented and anonymous. Any person, even a felon who is prohibited by federal law from buying a firearm, can walk up to any private seller and purchase a gun with no questions asked."
Wintemute said that his research shows that almost half the guns purchased at gun shows are bought from private sellers, and said he witnessed gun show customers walk away from transactions upon learning the sellers were licensed in order to find private sellers to buy from.
Senators Frank Lautenburg, D-NJ, and Jack Reed, D-RI, introduced a bill in January that would close the gun show loophole and require background checks on all guns purchases in the United States.
"That gun show loophole defies common sense," said Lautenberg. "This loophole has been open too long and it's time for Congress to pass my bill and close it."
Reed told ABC News that opposition to the bill from groups like the NRA has been constant and continuous, making it an uphill battle to pass the bill. "[The NRA] is in the business of preventing any sensible gun legislation," he said.
But some gun owners say legislators have already gone too far.