Adrian Lamo, the former hacker who reported Chelsea Manning to US authorities for leaking hundreds of thousands of classified State Department records, has died at the age of 37, according to a family Facebook post and a report from ZDNet, which cited two of Lamo's family members and a county coroner.

"With great sadness and a broken heart I have to let know all of Adrian's friends and acquittances that he is dead," his father, Mario Lamo, wrote in a Facebook post. "A bright mind and compassionate soul is gone, he was my beloved son."

It's not yet known how Lamo died.

Lamo was best known for notifying the US Army and FBI in 2010 of online chats he had with Manning, who at the time was a US Army intelligence analyst who went by the name Bradley Manning. According to a Wired article that broke the news, Manning befriended Lamo online and soon trusted him with a highly sensitive secret: that Manning was the person who had recently leaked a classified video to Wikileaks of a deadly US Army helicopter attack in Iraq. The video, which showed several innocent civilians being killed, went viral almost immediately after Wikileaks posted it and fueled criticism about the US-led war in Iraq.

Over an extended online discussion, Manning went on to confess to what at the time was the biggest known theft of classified documents. As reported by Kim Zetter and Kevin Poulsen, who were Wired reporters at the time:

From the chat logs provided by Lamo, and examined by Wired.com, it appears Manning sensed a kindred spirit in the ex-hacker. He discussed personal issues that got him into trouble with his superiors and left him socially isolated and said he had been demoted and was headed for an early discharge from the Army. When Manning told Lamo that he leaked a quarter-million classified embassy cables, Lamo contacted the Army and then met with Army CID investigators and the FBI at a Starbucks near his house in Carmichael, California, where he passed the agents a copy of the chat logs. At their second meeting with Lamo on May 27, FBI agents from the Oakland Field Office told the hacker that Manning had been arrested the day before in Iraq by Army CID investigators. Lamo has contributed funds to Wikileaks in the past and says he agonized over the decision to expose Manning—he says he's frequently contacted by hackers who want to talk about their adventures, and he has never considered reporting anyone before. The supposed diplomatic cable leak, however, made him believe Manning's actions were genuinely dangerous to U.S. national security. "I wouldn't have done this if lives weren't in danger," says Lamo, who discussed the details with Wired.com following Manning's arrest. "He was in a war zone and basically trying to vacuum up as much classified information as he could and just throwing it up into the air."

For the rest of his life, Lamo remained a figure who was reviled by most of Manning's many supporters and admired by some people for reporting the leaker.

The homeless hacker

Lamo first made a name for himself in the 2000s with a string of hacks on the networks of Microsoft, Yahoo, and and other Internet companies. According to this Wired profile, Lamo would intrude into the company networks, commit mostly harmless pranks, and then notify the company officials and sometimes the press of his feats. He reportedly infected a New York Times network with a backdoor, which he then used to obtain home phone numbers of more than 3,000 of the paper's op-ed contributors, including Vint Cerf, Warren Beatty, and Rush Limbaugh. During much of that time, Lamo lived out of a backpack and traveled the country on Greyhound busses and Amtrak trains. He often obtained his Internet access from university libraries and Kinko's shops.

In 2004, Lamo pleaded guilty to federal charges that stemmed from the NYT hack. According to Poulsen, Lamo was sentenced to six months of house arrest at his parents' home in Carmichael, California, followed by two years of probation. Poulsen—\who is also a former hacker who was prosecuted by federal authorities and knew Lamo socially—went on to report that, in later years, Lamo was diagnosed with Asperger's, a mild form of autism that Poulsen said is sometimes known as "geek syndrome" because it "makes social interactions difficult and can lead to obsessive, highly focused behavior."