But Holder cautioned reporters last week that the Espionage Act isn't the only law under which the Justice Department might charge Assange.
"I don't want to get into specifics here, but people would have a misimpression if the only statute you think that we are looking at is the Espionage Act," he said. "That is certainly something that might play a role, but there are other statutes, other tools that we have at our disposal."
Experts say Assange could also be charged with trafficking in stolen government property or conspiracy, if investigators can demonstrate a link between Assange and the alleged source of the leak, Army Private Bradley Manning.
Manning, who is believed to have stolen the documents in his role as a military intelligence analyst, is being held in a U.S. military prison in Quantico, Va. He likely faces charges for espionage.
As for liability of the news media, a recent report from the Congressional Research Service suggests there may be sufficient legal precedent to keep them off the hook.
"Leaks of classified information to the press have only rarely 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," the report reads.
"There may be First Amendment implications that would make such a prosecution difficult, not to mention political ramifications based on concerns about government censorship."