WASHINGTON — The disclosure that federal prosecutors have brought an unidentified criminal charge against Julian Assange, the WikiLeaks leader, follows years of government deliberations over the dilemma raised by competing desires to put him out of business and fears that doing so could create a precedent that would undermine press freedoms.

Many crucial details about what prosecutors have done remain unclear, including when the criminal complaint was filed, what specific charge or charges it contains, and what facts it is based upon. Depending on the answers, the Justice Department’s move could have very different implications for the traditional news media and First Amendment protections.

Why does charging Mr. Assange raise concerns about press freedoms?

Mr. Assange is not a traditional journalist, but what he does at WikiLeaks has also been difficult to distinguish in a legally meaningful way from what traditional news organizations, like The New York Times, do every day: seek out and publish information that officials would prefer to be kept secret, including classified national security matters.

The Justice Department has never charged journalists with violating the law for doing their jobs. But in recent years, it has become far more common to charge officials with a crime for providing information to reporters. Depending on the facts, the case against Mr. Assange could set a precedent further chilling investigative journalism.