NEW YORK — A terrorist hoping to buy an antiaircraft weapon could look no further than Facebook, which in recent years has been hosting sprawling online arms bazaars, including handguns, heavy machine guns, and guided missiles.
The Facebook posts suggest evidence of large-scale efforts to sell military weapons coveted by terrorists and militants. The weapons include many distributed by the United States to security forces and their proxies in the Middle East. These online bazaars, which violate Facebook’s recent ban on the private sales of weapons, have been appearing in regions where the Islamic State has its strongest presence.
This week, after The New York Times provided Facebook with seven examples of suspicious groups, the company shut down six of them.
The findings were based on a study by the private consultancy Armament Research Services, or ARES, about arms trafficking on social media in Libya, along with reporting by the Times on similar trafficking in Syria, Iraq, and Yemen.
Many sales are arranged after Facebook users post photographs in closed and secret groups; the posts act roughly like digital classified ads on weapons-specific boards. Among the weapons displayed have been heavy machine guns on mounts that are designed for antiaircraft roles and that can be bolted to pickup trucks, and more sophisticated and menacing systems, including guided antitank missiles and an early generation of shoulder-fired heat-seeking antiaircraft missiles.
The report documented 97 attempts at unregulated transfers of missiles, heavy machine guns, grenade launchers, rockets, and anti-matériel rifles, used to disable military equipment, through several Libyan Facebook groups since September 2014.
Many of these weapons left Libyan state custody in 2011, as depots were raided by rebels and looters.
Machine guns and missiles form a small fraction of the apparent arms trafficking on Facebook and other social media apps, according to Nic R. Jenzen-Jones, the director of ARES and an author of the report.
Examinations by the Times of Facebook groups in Libya dedicated to arms sales showed that sellers sought customers for a much larger assortment of handguns and infantry weapons.
The rifles have predominantly been Kalashnikov assault rifles, which are used by many militants in the region, and many FN FAL rifles, which are common in Libya.
All of these solicitations violate Facebook’s policies, which since January have forbidden the facilitation of private sales of firearms and other weapons, according to Monika Bickert, a former federal prosecutor who is responsible for developing and enforcing the company’s content standards.
Social media-based weapons markets in Libya are not unique. Similar markets exist in other countries plagued in recent years by conflict, militant groups, and terrorism, including arms-sales Facebook groups in Iraq, Syria, and Yemen.
It is not clear how extensive arms trafficking on the site has been, but the rate of new posts has been unmistakably brisk, with many groups offering several new weapons a day. Jenzen-Jones said that ARES documented 250 to 300 posts about arms sales each month on the Libya sites alone, and that sales appeared to be trending up.
Overall, using data from arms-sales Facebook groups across the Middle East, he said, “We’ve got about 6,000 trades documented, but it’s probably much bigger than that.’’
Bickert said the most important part of Facebook’s effort “to keep people safe’’ was to make it easy for users to notify the company of suspected violations, which can be done with a click on the “Report’’ feature on every Facebook post.
ARES has documented many types of buyers and sellers. These include private citizens seeking handguns as well as representatives of armed groups buying weapons that require crews to be operated effectively or appearing to offload weapons that the militias no longer wanted.
Different markets have different characteristics. In Libya, fear of crime seemed to drive many people to buy pistols, Jenzen-Jones said.
In Iraq, the Facebook arms bazaars can resemble inside looks at the failures of American train-and-equip programs, with sellers displaying a seemingly bottomless assortment of weapons provided to Iraq’s government forces by the Pentagon during the long US occupation. Those include M4 carbines, M16 rifles, M249 squad automatic weapons, MP5 submachine guns, and Glock semi-automatic pistols. Many of the weapons shown still bear inventory stickers and aftermarket add-ons favored by US forces and troops.
