When an interim engineering dean at the Johns Hopkins University asked a well-known cryptography professor to remove a blog post about the National Security Agency from university servers, he said he did so because he feared "legal consequences."
Hopkins never defined those perceived consequences, but the concern was based on professor Matthew D. Green's linking in the post to articles from The New York Times, ProPublica and the Guardian. Those stories discussed and shared portions of leaked classified materials apparently documenting how the National Security Agency undermined encryption technologies meant to keep Americans' online information private.
The university ultimately reversed Dean Andrew Douglas' decision and found his legal fears to be unfounded, but Douglas is hardly the first person to have them.
The legality of sharing or linking to already published classified materials — or even pulling them up on one's computer screen at work — has been an issue for legal scholars, government agencies and a broad array of institutions with federal connections.
Recent high-profile prosecutions, and the 35-year prison sentence given to WikiLeaks leaker and Army analyst Chelsea Manning, have driven the issue further into the minds of Americans and their representatives in Congress.
A complex system of federal laws restricts the distribution of classified information — a common penalty is 10 years in prison per leak. But experts say those penalties have almost exclusively been applied to people who use their access to get and release information.
Whether others could be prosecuted for further sharing the information is far less clear.
According to a congressional report, it's a lot easier for the government to prosecute leakers than the news organizations that publish the documents they release. People like Green, who share information that is already a part of the public discussion, are another step removed from the initial disclosure.
Unlike many of his Hopkins colleagues at the Johns Hopkins Applied Physics Laboratory, where the concern about his blog post arose, Green lacks a security clearance or a research contract with the federal government.
The Congressional Research Service report, published Monday, said the Espionage Act is one of several criminal laws that cover classified information. But those statutes "have been used almost exclusively to prosecute individuals with access to classified information (and a corresponding obligation to protect it) who make it available to foreign agents, or to foreign agents who obtain classified information unlawfully while present in the United States."
Civil statutes could also allow federal employers to fire or otherwise punish employees and contractors who have leaked information. Those are usually backed up with nondisclosure agreements that employees and contractors sign.
"While prosecutions appear to be on the rise, leaks of classified information to the press have relatively infrequently been punished as crimes, and we are aware of no case in which a publisher of information obtained through unauthorized disclosure by a government employee has been prosecuted for publishing it," said the report, written by legislative attorney Jennifer K. Elsea.
"There may be First Amendment implications that would make such a prosecution difficult, not to mention political ramifications based on concerns about government censorship."
The issue involves the legal standard of prior restraint, protections granted to reporters engaged in "routine newsgathering" and other considerations under the First Amendment.
Ultimately, whether or not publication of classified information can be punished "likely turns on the value of the information to the public weighed against the likelihood of identifiable harm to the national security, arguably a more difficult case for prosecutors to make."
Jay Rosen, a journalism professor and free-speech advocate at New York University, said fears of legal repercussions tied to published-but-still-classified documents remain alive and well in part because the nation's laws on classified documents are confusing.
Still, he said, Hopkins officials should have done more homework before attempting to silence an influential professor for linking to mainstream media websites on a blog.
"If it's not a crime, or at least it's not a prosecutable crime, to publish classified information, under what theory is it a crime to link to published classified information?" Rosen asked.