This case requires us to interpret the Freedom of Information Act (FOIA), 5 U. S. C. § 552. FOIA does not apply if the requested data fall within one or more exemptions. Exemption 7(C) excuses from disclosure "records or information compiled for law enforcement purposes" if their production "could reasonably be expected to constitute an unwarranted invasion of personal privacy." § 552(b)(7)(C).