NEW YORK >> The thorny issue of Internet privacy was taken up by a New York state appeals court Thursday, as judges seemed to be troubled that prosecutors in Manhattan had secretly searched the entire Facebook accounts of about 300 people who were not charged with a crime.

But the judges also questioned whether Facebook had a legal right to challenge the search warrants on behalf of its users, no matter how broad or questionable in scope the warrants were.

The five-judge panel in Manhattan, led by Presiding Justice Luis A. Gonzalez, of the Appellate Division for the 1st Department, must determine if Facebook and other social media companies can challenge search warrants in court when they believe the government’s request tramples on the right of their customers to be protected from unreasonable searches.

The case — known formally as "In Re 381 Search Warrants Directed to Facebook Inc." — is being closely watched by civil libertarians and other social media companies. Several tech giants, including Google, LinkedIn and Twitter, have filed amicus briefs. So has the New York Civil Liberties Union.

The search warrants were signed last year by Justice Melissa Jackson on the strength of a 96-page affidavit that has never been made public.

The warrants ordered Facebook to turn over every scrap of information in the accounts of 381 people, including private photos and conversations. That trove of information was used to obtain indictments for disability fraud against more than 130 police officers and other former public employees. Jackson also prohibited Facebook from informing its customers about the searches.

Ben Rosenberg, an assistant prosecutor, told the appellate judges that 302 of the people whose accounts were searched were never charged with fraud, though photos and other data from about 30 of those accounts were used as evidence against others.

That the government had seized the accounts of hundreds of people not charged troubled some of the judges. Justice Sallie Manzanet-Daniels sharply asked Rosenberg why prosecutors continued to "keep 302 people’s lives in their offices."

"There is no question these Facebook accounts are like someone’s home," she said. "Pictures, letters, conversations. You could do a physical search warrant and not get a smidgen of what you get out of Facebook."

Justice Judith J. Gische said "nobody wants the district attorney to have personal files" on people who are not indicted or the subject of a continuing investigation. But she noted that state law does not allow people to appeal search warrants, a point later echoed by Justice Dianne T. Renwick.

"I think it’s clear that we as a bench perceive something troubling about what’s going on, but is this something that should be addressed legislatively?" Gische said. "Is it really a legislative fix and not a court fix?"

The Manhattan district attorney’s office contends Facebook and other social media companies have no more right to challenge a search warrant than the landlord of a physical storage company would when it is searched. Search warrants are approved by state judges and generally can be challenged only by criminal defendants in pretrial hearings, Rosenberg said.

But Facebook’s lawyer, Thomas Dupree, argued the company was being directed to perform the searches, format the data and deliver it to prosecutors. That makes the warrants "different from a typical search warrant where you stand aside and let the police come in with a box," and gives a media company the right to refuse to do the search if it thinks it is illegal, just as it can challenge an overly burdensome subpoena in court.

"There is no possible justification for the warrants they served on us," Dupree said, adding that the private information of hundreds of people was "swept up in the government dragnet."

"The government’s logic is chilling," he said. "Under the government’s position, they could seize the accounts for everyone in New York City and indict one person."

Gonzalez focused his questions on whether the government’s request for information could be considered a subpoena, or some hybrid mix of a warrant and a subpoena, under the federal Stored Communications Act. If so, he said, that would give Facebook the standing to contest them. He noted that the language used in the warrants seemed to resemble the broad language in subpoenas, which a company may challenge as overly broad or burdensome.

"I think it is reasonable for Facebook to argue this language may turn what the people characterize as a warrant into a hybrid of a subpoena," he said.