Food and Drug Administration (FDA) Commissioner Scott Gottlieb this week called on Internet service providers and social media companies to more carefully monitor online sales of opioids.

“We find offers to purchase opioids all over social media and the Internet, including Twitter, Facebook, Instagram, Reddit, Google, Yahoo and Bing,” Gottlieb said at the National Rx Drug Abuse and Heroin Summit in Atlanta. Many illicit drugs that enter the U.S. are bought and sold online, including drugs laced with fentanyl, he said.

Gottlieb plans to meet with leaders of Internet companies and advocacy groups “to identify technology gaps and new solutions,” The Wall Street Journal reports. Such solutions might include search algorithms to alert potential buyers about treatment programs and the deadly risks of opioids.