New York and Massachusetts attorneys general are demanding that Facebook hand over information about how Cambridge Analytica used its data. They announced a joint investigation today following reports over the weekend that Cambridge Analytica improperly acquired data on 50 million Facebook users, which it used as part of President Trump’s 2016 campaign.

According to The New York Times and The Observer, the co-founder of Cambridge Analytica, Christopher Wylie, led an initiative starting in 2014 to help political campaigns profile voters. As part of the project, the company harvested data from Facebook through a third-party quiz app.

New York Attorney General Eric Schneiderman and Attorney General Maura Healey of Massachusetts announced a joint investigation today. As part of the investigation, they’re requesting all terms of use, privacy policy, and all other notifications Facebook users have received about data collection dating from 2013 to now, according to a person familiar with the matter. The attorneys general are also looking for Facebook to show any requests it made to Cambridge Analytica asking it to delete Facebook user data.

Cambridge Analytica, which is partly owned by hedge fund billionaire Robert Mercer, played a role in Trump’s 2016 presidential campaign, and the connection raises continued concerns over the influence Facebook had in the election.

“Consumers have a right to know how their information is used — and companies like Facebook have a fundamental responsibility to protect their users’ personal information,” Eric Schneiderman said in a statement to The Verge, “Today’s demand letter is the first step in our joint investigation to get to the bottom of what happened.”

He added, “New Yorkers deserve answers, and if any company or individual violated the law, we will hold them accountable.”

Maura Healey told The Verge, “As attorney general, my job is to protect consumers in Massachusetts. Companies that control huge amounts of personal data have a legal obligation to guard against theft and misuse of that information.”

She added, “We are investigating to find out how and why this data was shared by Facebook and whether the appropriate steps were taken to protect it against misuse and manipulation.” Healey had originally tweeted on March 17th that an investigation was forthcoming.