Twitter’s recent embrace of the tech industry’s do-not-track standard has drawn praise from top Republicans on the House Energy and Commerce committee. But the company’s announcement that it will use new methods of highlighting “relevant” users for new users to begin following is drawing questions from two of those GOP committee members, Reps. Joe Barton (Texas) and Cliff Stearns (Fla.), who on Friday sent a letter to Twitter CEO Dick Costolo asking about the ways the company collects and tracks user information.

In the letter, obtained by The Hill, Barton and Stearns explained that they want to know exactly what kinds of personally identifiable information Twitter collects.

{mosads}They also are interested in what kind of information Twitter plans to use to highlight users for people to follow. “How will Twitter be able to determine what user accounts are ‘relevant’ to a new user without any history of user activity?” they asked.

The questions from Barton and Stearns focus mostly on the methods of data collection Twitter uses, specifically the definition of the “Twitter ecosystem” as described by Costolo and others.

Other questions pertain to how long Twitter stores user data after deletion, and whether Twitter truly deletes a user after he asks to be deleted from the system.

The congressmen expect Costello to respond no later than June 16.

A Twitter spokesman did not immediately respond to a request for comment.