And not get punished for it, that's the question the Supreme Court decided today:
The Supreme Court declared today, in a ruling affecting millions of government employees, that the Constitution does not always protect their free-speech rights for what they say on the job.
In a 5-to-4 decision, the court held that public employees' free-speech rights are protected when they speak out as citizens on matters of public concern, but not when they speak out in the course of their official duties.
Hence, you can fire them in the latter case and probably harass them in other ways, too. The specific case that was decided was this one:
In this case, the Los Angeles deputy prosecutor, Richard Ceballos, complained to his bosses in early 2000 that after being alerted by a defense lawyer, he had found "serious misrepresentations" in an affidavit used to obtain a search warrant.
Discussions with his superiors were heated, and a trial court rejected challenges to the warrant. In the aftermath, Mr. Ceballos contended, he was reassigned and denied a promotion. He filed an employee grievance, which was denied based on a finding that he had not suffered any retaliation, despite his claim to the contrary.
Mr. Ceballos took his case to federal district court, which threw it out after accepting his employer's argument that the actions Mr. Ceballos complained about were explainable by legitimate staffing needs. But the United States Court of Appeals for the Ninth Circuit reversed the lower court, concluding that Mr. Ceballos's free-speech rights had indeed been violated.
In reversing the Ninth Circuit today, Justice Kennedy noted that the Supreme Court has made it clear in previous rulings "that public employees do not surrender all their First Amendment rights by reason of their employment." On the other hand, he wrote, "When a citizen enters government service, the citizen by necessity must accept certain limitations on his or her freedom."
The newly arrived justices Alito and Roberts voted with the majority, by the way, so I wouldn't invest in whistle futures.