On 7th December 2010, Dianne Feinsteinn wrote in WSJ:
When WikiLeaks founder Julian Assange released his latest document trove—more than 250,000 secret State Department cables—he intentionally harmed the U.S. government. The release of these documents damages our national interests and puts innocent lives at risk. He should be vigorously prosecuted for espionage.
The law Mr. Assange continues to violate is the Espionage Act of 1917. That law makes it a felony for an unauthorized person to possess or transmit “information relating to the national defense which information the possessor has reason to believe could be used to the injury of the United States or to the advantage of any foreign nation.”
The Espionage Act also makes it a felony to fail to return such materials to the U.S. government. Importantly, the courts have held that “information relating to the national defense” applies to both classified and unclassified material. Each violation is punishable by up to 10 years in prison.
Dianne Feinstein is the US Senator from California since 1992: she was also Mayor of San Francisco from 1978 to 1988. She graduated from Stanford University in 1955: her degree is in History. She is not a lawyer, any more than I am, and while I respect her decades of political acumen, I doubt that she took legal advice before she wrote that column in the Wall Street Journal.