Applying the US Espionage Act to third-party publishers of classified information like WikiLeaks would violate protected speech rights, the American Civil Liberties Union (ACLU) told members of the House Judiciary Committee Thursday.

"If the Espionage Act were to be applied to publishers, it would have the unconstitutional effect of infringing on the constitutionally protected speech rights of all Americans, and it would have a particularly negative effect on investigative journalism – a necessary and fundamental part of our democracy," the ACLU said in a statement (.pdf).

"In the current environment, it would be all too easy for inflamed public passions to serve as the basis for arguments to justify broadening even further the proscriptions of the law. Instead, Congress should stand clear-eyed and firm against arguments based on passion, not reason – and narrow the Espionage Act to those who leak properly classified information."

"[W]e urge Congress to resist the urge to broaden the Espionage Act's already overbroad proscriptions and, instead, to narrow the Act’s focus to those responsible for leaking properly classified information to the detriment of our national security," they continued. "Publishers who are not involved in the leaking of classified information should be praised by our society for their contributions to public discourse, not vilified as the co-conspirators of leakers with whom they have no criminal connection."

Government documents are too easy to classify, which has resulted in the classification of thousands of documents that pose no real risk to national security if released, according to the ACLU.

"Documents that are unnecessarily classified under such a system have the effect of grossly expanding the penalties of the Espionage Act to the release and publication of documents having purely innocuous content – but which happen to be designated as secret."

The ACLU urged Congress to amend the Espionage Act by removing all references to "publication" from the legislation and to improve the current classification system.

The committee's Thursday hearing on "the Espionage Act and the Legal and Constitutional Issues Raised by WikiLeaks" included a number of legal scholars and attorneys, including Ralph Nader.

Benjamin Wittes, a senior fellow in Governance Studies at The Brookings Institution, warned Monday that applying the Espionage Act to WikiLeaks founder Julian Assange could make "felons of us all."

Under the Act, anyone "having unauthorized possession of" information relating to the national defense, or information that could be "used to the injury of the United States or to the advantage of any foreign nation" may be prosecuted if he or she publishes it or "willfully retains" it.

"By its terms, it criminalizes not merely the disclosure of national defense information by organizations such as Wikileaks, but also the reporting on that information by countless news organizations," Wittes wrote on his blog. "It also criminalizes all casual discussions of such disclosures by persons not authorized to receive them to other persons not authorized to receive them–in other words, all tweets sending around those countless news stories, all blogging on them, and all dinner party conversations about their contents."

The State Department has argued that Assange is not "journalist" or "whistleblower," but a "political actor" with his own agenda.