Republican Sen. Marsha Blackburn (Tenn.) and Democrat Sen. Richard Blumenthal (Conn.) on Tuesday questioned the social media platform Pinterest about its practices for identifying, moderating and removing content that may be sexually suggestive or harmful to minor users. 

The senators in a letter to Pinterest CEO Bill Ready say Pinterest “has fallen short” of its “aspirations” about protections for young people on the platform.

The social media app allows users to both upload their own content and to save, or “pin,” images to scrapbook-style “boards,” and the senators’ letter cites an NBC News report from earlier this month highlighting that adult male users were able to create boards “dedicated to the sexualization of underage girls.” 

The NBC News report found that content uploaded by minor girls to the platform were then saved on boards with titles like “Sexy little girls” and “guilty pleasures” — and images of “visibly underage girls, including toddlers” were found to be suggested by Pinterest’s recommendation engine. 

“This included photos and videos of young children dancing and posing in clothes like pajama shorts, bathing suits, and leotards. Even more egregious, Pinterest apparently took little to no action to prevent adult men from posting sexually suggestive comments on minors’ photos and messaging them directly,” the senators wrote in their letter. 

Blackburn and Blumenthal called on Ready to explain Pinterest’s practices for identifying and removing pins, boards and comments “that are sexually suggestive of minors and/or may constitute child sexual abuse material, sexual trafficking of minors, or enticement.”

The senators also ask whether Pinterest performs its content moderation in-house, whether the platform has any stops to keep minors from receiving communication from adult users and whether Pinterest has any restrictions to keep minors from being followed by adult users, among other questions.

Blackburn and Blumenthal called the NBC News report “particularly disappointing given that Pinterest has branded itself the ‘last positive corner of the internet.’” Pinterest unveiled new safety features in the wake of the report, according to NBC News, which enable users to report accounts and boards for inappropriate content.

The senators acknowledged that Pinterest has “taken steps to address several of the issues” in the report, but argued that “it should not have taken national media coverage of such graphic misuse targeting young children to prompt action.”

The pair of bipartisan senators who sent the letter Tuesday are co-sponsors of the Kids Online Safety Act.