News Summary: SEC questioned Facebook pre-IPO

THE DISCLOSURES: On Friday, Facebook released letters it had with federal regulators ahead of its initial public offering of stock. The filings are a usual part of the IPO process.

THE TOPICS: Among other things, federal regulators wanted to know more about the revenue it gets from mobile devices, its $1 billion deal to buy Instagram and the control CEO Mark Zuckerberg has over the company.

RESULTS: As all companies do, Facebook Inc. amended its regulatory documents several times ahead of IPO. But the communications leading to those changes weren't public until now.