US congressmen have demanded more details about the way applications on Facebook handle user information.
US representatives Edward Markey and Joe Barton made the call in a letter to Facebook founder Mark Zuckerberg, according to US reports.
The letter follows a report by The Wall Street Journal which revealed that privacy breaches affected tens of millions of users.
The paper said the 10 most popular Facebook applications had been sending users' personal identifying information to advertising and internet tracking companies.
But Markey and Barton want Zuckerberg to respond to 18 questions by the end of October.
The congressmen's questions include the number of users affected by the privacy breaches, the specific nature of the data transmitted from the third-party applications, which Facebook terms were violated, the number of third-party applications in violation, and the procedures and guidelines Facebook has in place to detect and prevent this type of breach.
They also want to know what policy or procedural changes Facebook plans to ensure users have better control over their data and over their use of third-party apps.