A 22-year-old U.S. intelligence analyst has been arrested for allegedly giving classified combat footage of a U.S. helicopter crew killing civilians to Wikileaks, an online repository of leaked documents. The footage made international headlines because it appeared to show a helicopter crew deliberately killing civilians including two Reuters journalists.

Former hacker Adrian Lamo told the BBC that he turned Spc. Bradley Manning in because he was concerned about national security. Lamo claims that Manning "boasted" to him about sending combat footage and documents to Wikileaks.

Wired analyzed transcripts of the chats between Manning and Lamo, a legendary former gray hat hacker. Manning allegedly claimed to have leaked the video, footage of the Garani air strike in Afghanistan, a classified security assessment of Wikileaks, and 260,000 diplomatic cables to Wikileaks. The assessment of Wikileaks was published on the site. However, according to the BBC, Wikileaks denies receiving the diplomatic cables.

A childhood friend of Manning's says that Manning confided in January that he was debating whether to leak some classified information. “He wanted to do the right thing,” Tyler Watkins told Wired. “That was something I think he was struggling with.”