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The bipartisan Mayors Against Illegal Guns coalition today announced the results of a major investigation into online gun sellers, finding that hundreds of high-volume private sellers are undermining public safety by transferring tens of thousands of firearms every year over the Internet without conducting the background checks intended to ensure dangerous people cannot acquire firearms. In September, Mayors Against Illegal Guns released the first-ever national investigation into online gun buyers that found thousands of people already barred by existing Federal law from purchasing guns are flocking to the Internet to evade background checks and acquire guns illegally. This new report, which examines gun sellers, concludes that nearly one-in-three gun ads on a single website – – are posted by high-volume sellers, who are selling more than 34 firearms a year without a license, despite the fact that federal law requires anyone “engaged in the business” of selling guns to obtain a Federal Firearms License (FFL). At this rate, these unlicensed sellers would transfer more than 243,800 guns each year, many in violation of federal law. The investigation – conducted between August 2013 and October 2013 – also found that in addition to posting numerous guns for sale, 58 percent of high-volume sellers contacted by investigators voluntarily provided at least one additional indicator that they were illegally “engaging in the business,” including selling guns new or in original packaging, selling guns for profit, and buying and reselling guns within a short period of time.
The full report – “In the Business, Outside the Law: How Unlicensed Sellers Flood the Internet with Guns” – is available at Mayors Against Illegal Guns Co-Chair and New York City Mayor Michael R. Bloomberg announced the findings in a press conference at City Hall.
“On December 14th, we will mark a very somber anniversary and pause to remember what happened at Sandy Hook Elementary School one year ago,” said Mayor Bloomberg. “Our report shows much more clearly needs to be done to prevent unlicensed sellers of firearms from illegally flooding the Internet with weapons and the result is a massive online, unregulated, second-hand firearms market that threatens public safety. These findings clearly tell us that law enforcement, legislators and web sites all need to take steps to choke off this potentially deadly stream of illegal firearms sales.”
“Unregulated Internet gun sales make it far too easy for an illegal gun to fall into the wrong hands,” said Mayors Against Illegal Guns Co-Chair and Boston Mayor Thomas M. Menino. “It’s time for our leaders in Washington to stop ignoring the will of the people they represent. We must prioritize the safety of our communities by passing common-sense background check legislation that will help save lives.”
While licensed gun dealers are subject to certain public safety regulations – including conducting background checks of buyers and accepting periodic inspections by law enforcement – so-called “private sellers” are not held to these same standards. A private seller is considered anyone who makes occasional gun sales or sells from their personal collection. These individuals are not required to have a license and do not need to conduct criminal background checks on gun sales. With the Internet providing a host of websites for private sellers to conduct business, it is now easier than ever for criminals and other dangerous individuals to obtain guns through unregulated online sales.
This new investigation examines a dark corner of this vast private marketplace: unlicensed “private sellers” who are offering guns for sale in such volume that they are effectively acting as dealers – but not conducting the background checks that federal law and public safety require. The findings show that a small share of gun sellers are blurring the line between private sellers and licensed dealers, undermining the background check system, and putting guns in the hands of killers.
This report is the latest in a series of investigations led by Mayor Bloomberg and Mayors Against Illegal Guns into the potential dangers of online gun sales. In September 2013, the coalition released “Felon Seeks Firearm, No Strings Attached,” the first-ever national investigation into individual buyers with criminal records seeking to illegally acquire firearms via online gun sales. In December 2011, Mayor Bloomberg announced the first-of-its-kind undercover investigation of illegal online gun sales in the report “Point, Click, Fire,”which found that 62 percent of private sellers were willing to commit a felony by selling firearms to people who likely could not pass a background check.
The Investigation
Unlike storefronts or tables loaded with merchandise at gun shows, the Internet does not reveal the number of guns a seller is advertising for sale. It provides sellers with a sense of anonymity, and the ability to offer no more information than the model of the gun they are offering and the city or state where they are located.
Though countless websites facilitate gun sales, this investigation focused on just one – – because it is large, primarily serves self-identified “private sellers,” and hosts gun ads in all 50 states. But the web architecture of links all of the gun listings posted by any specific user – presumably to allow buyers to review a seller’s whole inventory. By observing these networks of linked postings over time, this investigation paints a first-of-its-kind picture of the volume of private sales taking place on, and the “private sellers” conducting this illegal business without background checks.
During an eight-week period between August 17, 2013 and October 10, 2013, investigators for Mayors Against Illegal Guns retrieved all 125,263 ads posted on by self-described private sellers. Each ad was assigned a seller identification number, and any ads posted by the same user were given a matching seller identification number, along with any ads linked to them. Over time, this data mapped out the contemporaneous gun ads listed by any given seller and the distribution of sales volume across the total population of sellers – from those who posted a single gun listing to those who posted tens or hundreds. This technique produces a conservative estimate of sellers’ total gun listings because it only links ads together that are online contemporaneously.
Federal law provides no definitive legal standard for a “high volume” of private sales. But, for the purpose of this investigation, Mayors Against Illegal Guns focused on sellers who listed five or more guns during the period of observation. Sellers who posted ads at this rate over a year would list more than 34 guns annually. In subsequent calls, investigators found that more than half of high-volume sellers voluntarily gave additional indications that they were indeed engaging in the business of selling guns without a license.
The Results
The investigation found that:
  • Nearly one-in-three gun ads (29 percent) on are posted by high-volume unlicensed sellers, many of whom are likely “engaged in the business” of selling firearms in violation of federal law. At that rate, these sellers would illegally transfer 243,800 guns each year.
  • In follow-up conversations with a subsample of high-volume sellers, more than half (58 percent) gave additional indications that they were illegally “engaging in the business” of selling guns. Indicators include selling guns new or in original packaging, selling guns for profit, and buying and reselling guns within a short period of time.
  • In the minority of states that go beyond federal law and require private sellers to conduct background checks, most sellers follow the law and gun sales are safer as a result. In states that require private sellers to conduct background checks for some or all gun sales, 73 percent of sellers told the would-be buyer they would need to comply with the state’s background check law.
Law enforcement, legislators, and websites that host gun ads all have a responsibility to ensure firearm commerce is conducted lawfully and safely. The following are recommendations for:
Law Enforcement
  • ATF should define and promulgate a clear standard explaining what it means to “engage in the business” of selling firearms, and federal prosecutors should consistently and forcefully police the boundary between licensed dealers and private sellers.
  • The online market presents unique opportunities for sellers to operate at a large scale and for purchasers to operate anonymously, and merits special attention from law enforcement. ATF should create an Internet unit to monitor online gun sales and crack down on high-volume, unlicensed sellers.  
  • In 2012, 6.6 million guns were transferred through private sales without background checks, and dangerous people exploit this loophole to evade background checks and get armed. Congress should pass legislation requiring private sellers in commercial settings to uphold the same background check requirement that dealers already abide by.
  • Congress should also pass a federal gun trafficking statute so that private sellers who knowingly transfer a firearm to a prohibited person can be held fully accountable.
Websites Hosting Gun Ads
  • and other online gun marketplaces should take greater responsibility for the gun sales they facilitate. Some of the steps the sites should take include:
  • Monitoring high-volume sellers. Websites could issue direct warnings to sellers who appear to be engaging in the business of selling firearms without a license, and report repeat offenders to law enforcement. 
  • Requiring greater transparency from buyers and sellers. Websites should require sellers to register with the website – including credit-card verified evidence of their identity – before they advertise guns, and should require buyers to do the same before they make purchase them. 
  • Recommending and facilitating voluntary background checks for private sellers.Websites like created an “FFL Holder Network” to conduct background checks for private sellers on the website, and 17,000 gun dealers have already joined voluntarily. Other websites should adopt a similar model.