In an open letter today, the National Association of Attorneys General called on Facebook to abandon plans for an Instagram platform focused on children under the age of 13. The letter is signed by 44 different state-level attorneys general (including non-states like Guam, Puerto Rico, and the Northern Mariana Islands), representing a majority of US territories.

“It appears that Facebook is not responding to a need, but instead creating one, as this platform appeals primarily to children who otherwise do not or would not have an Instagram account,” the letter reads. “The attorneys general urge Facebook to abandon its plans to launch this new platform.”

Plans for the child-focused Instagram were first reported by Buzzfeed News in March, and subsequently confirmed by the company. But while internal emails reported by Buzzfeed identified the project as a company priority, Facebook insisted at the time that there was no specific timeline for release.

While the letter has no formal legal power, it emphasizes the significant legal risk Facebook will face in undertaking the project. In the US, children under 13 are subject to enhanced legal protections under the Children’s Online Privacy Protection Act (or COPPA), which places particularly stringent rules against data collection.

Social networks have traditionally complied with the act by banning users under the age of 13, but it has not entirely protected them from regulatory action. Most recently, Google agreed to pay $170 million after a Federal Trade Commission investigation about the company’s data collection from YouTube videos featuring children’s content.

State attorneys general have been particularly active in the enforcement of COPPA protections, so the NAAG letter carries with it an implicit legal threat: if Facebook proceeds with its plans for an Instagram for kids, these same attorneys general will be watching very closely for COPPA violations and will be eager to file suit over any violations they find.

Reached for comment, Facebook said it would not sell ads on any Instagram app targeted at young children but did not back off on its interest in developing the app.

“We’ve just started exploring a version of Instagram for kids,” said Facebook policy representative Andy Stone. “We agree that any experience we develop must prioritize their safety and privacy, and we will consult with experts in child development, child safety and mental health, and privacy advocates to inform it. We also look forward to working with legislators and regulators, including the nation’s attorneys general. In addition, we commit today to not showing ads in any Instagram experience we develop for people under the age of 13.”