Is this supposed to be called treason?

I'm not sure of the definitions, but this is definitely not to be condoned.
From Wired.com:

U.S. Intelligence Analyst Arrested in Wikileaks Video Probe

By Kevin Poulsen and Kim Zetter

Federal officials have arrested an Army intelligence analyst who boasted of giving classified U.S. combat video and hundreds of thousands of classified State Department records to whistleblower site Wikileaks, Wired.com has learned.

SPC Bradley Manning, 22, of Potomac, Maryland, was stationed at Forward Operating Base Hammer, 40 miles east of Baghdad, where he was arrested nearly two weeks ago by the Army’s Criminal Investigation Division. A family member says he’s being held in custody in Kuwait, and has not been formally charged.

Manning was turned in late last month by a former computer hacker with whom he spoke online. In the course of their chats, Manning took credit for leaking a headline-making video of a helicopter attack that Wikileaks posted online in April. The video showed a deadly 2007 U.S. helicopter air strike in Baghdad that claimed the lives of several innocent civilians.
He said he also leaked three other items to Wikileaks: a separate video showing the notorious 2009 Garani air strike in Afghanistan that Wikileaks has previously acknowledged is in its possession; a classified Army document evaluating Wikileaks as a security threat, which the site posted in March; and a previously unreported breach consisting of 260,000 classified U.S. diplomatic cables that Manning described as exposing “almost criminal political back dealings.”

If you read the rest of the article you see that this 22 year old punk truly thinks he  is entitled to leak security secrets because he knows best.  He is a true disciple of the lefists who came into being during the Vietnam war and were persuaded of their moral superiority over any honest American citizen. Read more here.