The head of the Food and Drug Administration called out Facebook, Reddit, and Twitter, among other sites, for not doing enough to crack down on the online opioid trade. Scott Gottlieb, the FDA commissioner, spoke at the National Rx Heroin and Drug Abuse Summit Wednesday, and said he was “concerned” that internet companies didn’t seem to be doing anything about the prolific sale of prescription drugs online, and announced a plan to host a summit with Silicon Valley CEOs.

“We find offers to purchase opioids all over social media and the Internet, including Twitter, Facebook, Instagram, Reddit, Google, Yahoo, and Bing,” Gottlieb said. “But when it comes to opioids, we haven’t seen meaningful, voluntary actions.”

Drug overdose deaths in the US increased 11.4 percent from 2014 to 2015 (the most recent data we have), according to the Centers for Disease Control and Prevention. This amounts to 52,404 deaths 63 percent of which involved an opioid. And while widespread opioid addiction has a complicated web of causes, Gottlieb highlighted one area that has gone overlooked throughout much of the effort to combat the epidemic: the internet.

Gottlieb referred to a Senate investigation from January, where investigators posed as first-time fentanyl buyers to see how easy it was to buy the opioids online. They found it was, in short, ridiculously easy, immediately identifying six different websites where sales were facilitated. During the investigation, the team found “more than 500 financial transactions by more than 300 U.S.-based individuals totaling $230,000 to the six online sellers,” according to the report, and even identified seven people who died from fentanyl overdoses after buying the drugs online.

“Online sellers were quick to respond, unafraid of getting caught, and ready to make a deal,” Senator Rob Portman, chair of the Permanent Subcommittee on Investigations, said during a hearing about the investigation. “They offered discounts for bulk purchases and even tried to upsell us to carfentanil—a powerful synthetic opioid that is so strong it’s used as an elephant tranquilizer. Ordering these drugs was as easy as buying any other product online.”

The bulk of Gottlieb’s speech focused on reforming the prescription system to prevent people from getting hooked on opioids in the first place. But he also emphasized that he expects internet companies to step up on this issue, and said he plans to host a summit with top CEOs to strategize how to crack down on the online arm of this epidemic.

“We need to work together on shared solutions to address the problem of opioids marketing in the online space,” he said. “Until we do, we risk remaining behind the leading edge of this intractable and evolving crisis involving drugs that make life bearable for some patients, but are lethal for far too many others.”