A recent United States Supreme Court ruling limits protections for government workers who blow the whistle on official misconduct. New Justice Samuel Alito cast the deciding vote in the 5-4 decision.

Critics have said the ruling silences millions of workers who fear retribution for reporting corrupution or problems with government preparedness.

Supporters believe the ruling will protect governments from frivolous lawsuits filed by disgruntled whistleblowers.

The ruling was also the first sign of a shift in the Supreme Court’s balance since the departure of Justice Sandra Day O’Connor. Last year, O’Connor wrote an opinion encouraging whistleblowers to report sex discrimination in schools. The decision in the most recent case split along traditional conservative-liberal lines.

In the ruling, Justice Kennedy said that exposing government misconduct is important but he rejected the notion that the First Amendment shields from discipline the expressions employees make pursuant to their professional duties.

The ruling overturned an appeals court decision that said Los Angeles County prosecutor Richard Ceballos was constitutionally protected when he wrote a memo questioning whether a county sheriff’s deputy had lied in a seach warrant affidavit. Ceballos had filed a lawsuit claiming he was demoted and denied a promotion for exposing the lie.

Kennedy said the prosecutor’s superiors could discipline him if they thought the memo was inflammatory. "Official communications have official consequences, creating a need for substantive consistency and clarity. Supervisors must ensure that their employees’ official communications are accurate, demonstrate sound judgment, and promote the employer’s mission," Kennedy wrote.