WASHINGTON, D.C.

The Federal Trade Commission (FTC) recently responded to a report from Public Citizen by sending compliance reminder letters to more than 90 high-profile influencers and advertisers—but the watchdog group says that the letter had little effect.

Submitted in April, Public Citizen’s report alleged that 46 actors, musicians, athletes, and celebrities such as Victoria Beckham, Jennifer Lopez, and Sean “P. Diddy” Combs failed to disclose compensation for product endorsements appearing on Instagram, a violation of the FTC Act. Public Citizen wrote the FTC again in June, charging that its “attempt to educate paid influencers and brands about the importance of using disclosures” had failed to encourage compliance with regulations.

Blending self-promotion and endorsement, the Instagram platform can be difficult to police because the casual posting of pictures by a celebrity often disguises an endorsement if one exists. The FTC’s letter made it clear that it expects brands and influencers to make proper disclosures of material connections on Instagram, marking the first time that the FTC staff has targeted social influencers with disclosure guidance.