The Electronic Privacy Information Center filed a complaint against Facebook with the Federal Trade Commission (FTC) late last week that alleged that the site’s experiment with its users’ emotions via their Facebook Timelines was deceitful.

“At the time of the experiment, Facebook did not state in the Data Use Policy that user data would be used for research purposes. Facebook also failed to inform users that their personal information would be shared with researchers,” the complaint read.

The Center for Digital Democracy has said that they are also considering filing a complaint against Facebook, and the site is already facing an investigation in Britain. The study, which was conducted by Facebook and Cornell University, has drawn widespread criticism from around the web, and Facebook has tried to apologize for it while gently telling users that they did, in fact, sign up for things like this when they joined the site.

“When someone signs up for Facebook, we’ve always asked permission to use their information to provide and enhance the services we offer,” Facebook said in a statement. “Companies that want to improve their services use the information their customers provide, whether their privacy policy uses the word ‘research’ or not.”