Sen. Ed Markey (D-Mass.) says Facebook and Instagram need to do more to curb guns sales via social networking, including coming up with a better monitoring system than reliance primarily on user reporting.

Facebook, following letters from Markey on the subject last November and again in July, announced that neither it nor co-owned Instagram would allow firearms listings, but Markey says, citing media reports, that the social media sites are still being used to "pursue" those sales.

Facebook and Instagram told Markey that, since January, they have prohibited listings of peer-to-peer guns sales of any kind, they would continue to remove content when made aware of it and notify law enforcement "where appropriate," appropriate being where there is a "direct, credible risk to others' safety" or it is necessary to detect and prevent fraud or other illegal activity.

Peer-to-peer sales are as distinguished from postings by online retailers about gun purchases that are made off of Facebook. It also pointed out that even before the January policy change they had education efforts about peer-to-peer gun sales complying with relevant laws and regulations, and prevented minors from accessing that content when it became aware they were doing so.

"Despite the companies’ policies prohibiting those [gun] sales, it remains too easy for users to solicit and conduct private gun sales through Facebook and Instagram," said Markey. “While I commend the platforms’ facilitating the reporting of prohibited content related to gun sales by users, I urge Facebook and Instagram to redouble their efforts to develop and deploy technology that can enforce their gun-sales ban without relying so heavily on user reporting. Facebook and Instagram’s ban on private firearms sales should have the teeth it needs to be effective, so that it can truly prevent guns from falling into the hands of those who should not have them."