Daniel Ellsberg also praised an Army private, Bradley Manning, suspected of giving WikiLeaks thousands of sensitive U.S. documents.
Ellsberg told a Washington news conference Thursday the men were no more deserving of prosecution than the New York Times, which published the Pentagon Papers in 1971, or Washington Post reporter Bob Woodward for helping uncover the Watergate conspiracy.
Ellsberg then attended an anti-war rally and was among dozens arrested for protesting outside the White House.
The federal government is looking at whether it can prosecute Assange for releasing U.S. diplomatic cables and reports from the Iraq war.
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