Hill fallout continues from a report that Facebook and MySpace had transferred users personal information to marketing firms and other third parties without their knowledge.
The Wall Street Journal reported that tens of millions were affected by third-party applications that gathered personally identifiable information on users.
Sen. Jay Rockefeller (D-W. Va.), who has pushed for stronger online privacy protections, Tuesday asked Facebook CEO Mark Zuckerberg and MySpace president Michael Jones for more information about the breaches, saying they raised serious questions about enforcing their own privacy policies.
Among the questions Rockefeller wants answered are what other breaches there have been, what penalties are imposed on third parties who violate the sites' privacy policies, and, in the case of MySpace, why it says it can't control how third parties control or use information when other sites do.
"I fully intend to conduct oversight and formulate strong public policy that protects the privacy of American consumers," said Rockefeller to each executive.
Rockefeller's request follows a similar one by Reps. Joe Barton (R-Tex.) and Ed Markey (D-Mass.), co-chairs of the House Privacy Caucus, last week, giving the companies until Oct. 27 to respond.