On January 21, 2015, in Department of Homeland Security v. MacLean, the US Supreme Court held in a 7-2 decision that the “specifically prohibited by law” exception to the federal whistleblower statute (U.S.C. §2302(b)(8)(A)), which takes away any whistleblower protection for an employee who makes disclosures that are "specifically prohibited by law," did not apply to disclosures of sensitive security information made by a federal air marshal. Subject to certain exceptions, the federal whistleblower statute generally prohibits federal agencies from terminating an employee who discloses information reasonably believed to violate a law, rule or regulation or to be a substantial or specific danger to public health or safety. The Supreme Court examined the statutory language and found that the "specifically prohibited by law" exception applies only to disclosures prohibited by statute, not by regulations or rules. As a result, the air marshal's disclosures, which were not prohibited by an actual statute, were found to be protected whistleblowing activity. (No. 13-894, (U.S. Jan. 21, 2015).)

In 2006, a former federal air marshal, Robert MacLean, was terminated by the Transportation Security Administration (TSA) for disclosing “sensitive security information” to a television reporter. Three years earlier, in 2003, the TSA had briefed all federal air marshals, including MacLean, about a potential plot to hijack passenger flights. A few days later, MacLean learned that the TSA had cancelled all overnight missions from Las Vegas for a period of time. MacLean believed the cancellations were both dangerous and a violation of law requiring air marshals to be present on flights that presented a security risk. When he did not receive a satisfactory explanation about the cancellations from TSA officials, MacLean informed a television reporter of the cancellations. The TSA’s cancellation of MacLean’s missions was ultimately reversed after the story broke in the media. In 2004, as the TSA investigated the disclosures, MacLean admitted that he had disclosed the information to the reporter. Under regulations issued by the TSA in 2002, employees are prohibited from disclosing “sensitive security information,” including information about aviation security measures and about federal air marshal missions and deployment (49 CFR § 1520.7(j)). The TSA terminated MacLean for disclosing “sensitive security information” in violation of TSA regulations.

MacLean initially challenged his termination before the Merit Systems Protection Board (MSPB). He argued that his disclosures were protected whistleblowing activity under the federal Whistleblower Protection Act (WPA) (5 U.S.C. § 2302(b)(8)(A)). Under the statute, federal agencies may not take any personnel action against an employee (or applicant) who discloses information he "reasonably believes" to be a “violation of any law, rule, or regulation” or “a substantial and specific danger to public health or safety” (5 U.S.C. § 2302(b)(8)(A)). However, the statute provides exceptions to whistleblowing protection, including when the disclosures are “specifically prohibited by law.” The MSPB ruled that MacLean was not entitled to protection as a whistleblower because his disclosures were “specifically prohibited by law.” The US Court of Appeals for the Federal Circuit vacated the MSPB’s decision, finding that the statute that authorized the TSA’s regulations prohibiting the disclosure of “sensitive security information” did not specifically prohibit MacLean’s disclosures (49 U.S.C. § 114(r)(1)).

The US Supreme Court agreed to decide whether MacLean’s disclosure was “specifically prohibited by law” within the meaning of the exception in Section 2302(b)(8)(A).

On January 21, 2015, the Supreme Court affirmed the Federal Circuit’s decision, holding that the “specifically prohibited by law” exception to the federal whistleblower statute did not apply to the disclosures of sensitive security information made by MacLean. The Court examined the statutory language and found that:

In determining that a disclosure that is specifically prohibited by regulation is not "specifically prohibited by law" under the whistleblower statute exception, the Court relied on the text of the statute and found that:

The Supreme Court also addressed whether MacLean’s disclosure was prohibited by Section 114(r)(1), the statute which authorizes the TSA to promulgate regulations prohibiting the disclosure of sensitive security information. The Supreme Court found that Section 114(r)(1) gave the TSA authority to create a prohibition but did not create a prohibition itself.

The Government argued that providing whistleblower protection to individuals like MacLean would effectively put decisions about the confidentiality of sensitive security individuals in the hands of thousands of individual TSA employees, many of whom do not have access to some or all of the information behind TSA’s security decisions and judgments. The Court recognized this argument as valid but indicated that remedying this potential flaw in the whistleblowing statute lay in the hands of Congress, not the Court.

In the dissent, Justice Sotomayor, joined by Justice Kennedy:

The dissent pointed to the use of “shall” in Section 114(r)(1) as a statutory mandate directing the TSA to promulgate regulations for the specific purpose of preventing disclosures that would compromise the security of transportation. In the dissent’s view, the source of the prohibition on disclosing “sensitive security information” was Congress, not the agency. According to the dissent, Congress had “expressed its clear intent to prohibit such disclosures” in Section 114(r)(1).

The Supreme Court's decision in MacLean strengthens the whistleblower protection afforded to federal employees who disclose sensitive information. Federal employers must be careful when taking any personnel action against an employee for disclosing information that reveals a violation of a law, rule or regulation or a danger to public health or safety. Unless the employee's disclosure is specifically prohibited by an actual statute, terminating the employee because he disclosed such information may expose federal employers to liability for violating the WPA.