Potomac, Md. ? With his custom-made “humanist” dog tags and distrust of authority, Bradley Manning was no conventional soldier.

Ostracized by peers in Baghdad, busted for assaulting a fellow soldier and disdainful of the military’s inattention to computer security, the 22-year-old intelligence analyst styled himself a “hactivist.”

On Tuesday, the U.S. Army charged him with multiple counts of mishandling and leaking classified data and putting national security at risk.

Manning is suspected of leaking a classified video that shows a group of men walking down the street in Iraq before being repeatedly shot by Apache helicopters.

In a series of online chats in late May with a fellow computer geek, Manning claimed he had leaked a staggering 260,000 classified diplomatic reports, along with secret video of U.S. service members killing civilians, to the whistleblower website Wikileaks.org.

Whether or not Manning was the source, Wikileaks in April posted a video clips shot from a cockpit in 2007, of excited, laughing U.S. troops gunning down a group of men that included a Reuters news photographer and his driver. An internal military investigation concluded the troops acted appropriately, despite having mistaken camera equipment for weapons.

The case has drawn comparisons to Daniel Ellsberg’s leak 40 years ago of the Pentagon Papers, a top-secret history of the Vietnam War.

And it has bolstered perceptions that the Obama administration, despite a stated policy of open government, is as determined as its predecessors with keeping secrets.