The Supreme Court's 8-0 decision in Federal Communications Commission v. AT&T, Inc., No. 09-1279 (Mar. 1, 2011) [pdf], closes the door on corporate use of the personal privacy provision in FOIA Exemption 7(C).
The case involved a request for documents obtained from AT&T in a government investigation of alleged overcharging. AT&T opposed releasing them to the public under the Freedom of Information Act, arguing that some of the documents were covered by FOIA Exemption 7(C) because they are law enforcement records, the disclosure of which "could reasonably be expected to constitute an unwarranted invasion of personal privacy." 5 U.S.C. § 552(b)(7)(C). The Third Circuit sided with AT&T [pdf], but the Supreme Court reversed.
AT&T's argument was a linguistic one—corporations are entitled to invoke "personal privacy" because the statutory definition of "person" includes corporations. In the Court's view, the two terms are not so easily equated. Just as a corny joke need not involve corn, there is no necessary link between the defined term "person" and the phrase "personal privacy," which is not defined. Indeed, the Court concludes that AT&T's interpretation conflicts with common usage of the term "personal" and with other language used in the statute. According to the opinion in FCC v. AT&T, Congress intended to apply the personal privacy exemption to individuals, not corporations.