Federal prosecutors accidentally revealed the existence of secretly filed criminal charges against Julian Assange, the WikiLeaks founder who has been living for years in the Ecuadorean embassy in London.

Assange has been a target of the United States Justice Department since 2010, when WikiLeaks began publishing thousands of classified military and State Department documents obtained by Army intelligence analyst Chelsea Manning.

During the 2016 presidential campaign, WikiLeaks published thousands of emails hacked from the Democratic National Committee and from the Gmail account of Clinton adviser John Podesta.

It’s unknown what criminal charges have been filed against Assange. Their existence came to light in a three-page document filed by prosecutors in an unrelated case, apparently the result of a copy-and-paste error.

Text that described the reasons for sealing the charges included Assange’s name instead of the name of the individual who was the subject of the filing.

The Obama Justice Department spent years studying the possibility of charging Assange with a criminal offense but ultimately concluded that it could not charge him for publishing national security secrets without also charging publications including The New York Times, the Washington Post and any other media outlet that reported on leaked classified material.

There is no clear answer to the legal question of how to distinguish between different types of publishers.

Would printed newspapers have protection while digital publishers could be prosecuted? There also is no answer to the question of who should decide which publishers could face charges for publishing leaked national security documents.

If the DOJ has evidence that Assange participated in the theft of classified documents or the hacking of servers, it would have every reason to charge him.

However, if officials have filed criminal charges against Assange for publishing what others obtained and gave to him, the government’s action will chill investigative reporting and set the stage for serious misconduct and violations of the law to be permanently concealed behind a curtain of national security secrecy.