Nineteen bipartisan U.S. lawmakers have sent a letter to Meta CEO Mark Zuckerberg, expressing concerns over the company's failure to prevent ads for illegal drugs on Facebook and Instagram. The letter follows reports by The Wall Street Journal and Tech Transparency Project, which identified hundreds of such ads. These ads, featuring blatant references to drugs like cocaine and ecstasy, directed users to third-party platforms for purchase. Lawmakers criticized Meta for approving and monetizing these ads despite existing community standards and an ongoing federal investigation. Meta has stated that its systems are designed to proactively detect and reject violating ads and that it continues to invest in improving these systems. Zuckerberg is required to respond to the lawmakers' questions by September 6th.