The U.S. Department of Transportation (DOT) is looking to thwart the nation’s 10 largest airlines from monetizing passenger data or selling it to third parties.

Secretary of Transportation Pete Buttigieg announced the first industry-wide privacy review in a press release Thursday. The review will scrutinize the collection, handling, maintenance, and utilization of airline passengers’ personal information.

The DOT’s Office of Aviation Consumer Protection will specifically look at Allegiant Air, Alaska Airlines, American Airlines, Delta Air Lines, Frontier Airlines, Hawaiian Airlines, JetBlue, Southwest Airlines, Spirit Airlines, and United Airlines.

In August, the DOT warned airlines and ticket agents against monetizing or sharing data collected, as it would constitute unfair or deceptive practices and potentially result in civil penalties.

The DOT enforces compliance with the Children’s Online Privacy Protection Act (COPPA), sharing jurisdiction with the Federal Trade Commission (FTC) over ticket agents.

As part of the review, the DOT requested information from airlines regarding their policies and procedures on the collection, maintenance, handling, and use of passenger data; complaints related to mishandling of personal information; and details of privacy training provided to personnel.

In December, the FTC proposed enhancements to the COPPA rules to impose stricter restrictions on the use and disclosure of children’s data and address surveillance and data security concerns.