At the large public housing project in New York City where he lived, outsiders knew him as a quiet family man. But federal prosecutors say Hector Xavier Monsegur was an Internet saboteur known as Sabu.
During the Arab spring, prosecutors say he hacked into government Web sites in Tunisia, Yemen and Algeria. He helped coordinate attacks on credit card companies after they refused to accept donations to Wikileaks. Then, they said, he added another layer to the subterfuge by informing on his accomplices after he was caught by the FBI last spring.
His cooperation led to charges filed Tuesday against five people in the United States, Scotland, Ireland and England, including one other American, Jeremy Hammond, a 27-year-old from Chicago.
Monsegur's New York neighbors said that after his father and an aunt went to jail for drug dealing, the 28-year-old took over the job of raising his two young nieces.
"He was a quiet man, but he would smile when he passed by, and he talked to everybody," said neighbor Jorge Santiago, a 78-year-old retired truck driver who said he has known Monsegur all his life. "Everybody knew him."
In a telephone interview from her home outside Austin, Texas, the mother of one of the suspects, Hammond, told The Associated Press on Wednesday that her son was a brilliant computer whiz but apparently couldn't stop himself from applying his genius to "get the goat of America."
"He does have a good heart, but, I don't know, he just wants to make those who disagree with him suffer," Rose Collins said. "He thinks America is evil, has done everything wrong."
That made for some tension in the family. Collins described herself as a staunch conservative who has attended tea party rallies. Hammond's father, now jailed in a Chicago suburb awaiting trial on a charge of aggravated sexual abuse of a minor, was "very, very far left," Collins said. "So far off the charts that one more step he's going to fall off the planet."
Hammond, she said, was raised by his father after the couple split up and adopted his politics.
"He wants to end capitalism," she said.
Collins said her son could have done anything with his computer skills but had a penchant for using them to raise a ruckus. In high school, she said, he hacked into the school's mainframe computer to demonstrate its security vulnerabilities. He did the same thing when he went to college at the University of Illinois at Chicago, which earned him an expulsion, Collins said.
The university confirmed that Hammond was a computer science major but left without a degree in 2004. It wouldn't say whether he was kicked out, citing federal privacy laws.
A year later, Hammond was caught hacking in to a conservative website and stealing credit card information. He pleaded guilty and was sentenced to two years in prison.
Collins said she hopes her son is innocent.
"I'm praying for that," she said.
But she added that she has long admired his courage and passion for his political beliefs, even if she didn't share them.
"He's a braver man than me," she said.
Hammond is now jailed pending transport to New York, where he will face charges in a case in which Monsegur has already pleaded guilty.
Attempts to reach Monsegur on Wednesday were unsuccessful. His lawyer, Peggy Cross-Goldenberg, declined to comment. No one answered the door of his family's apartment in the Jacob Riis Houses, a public housing project that has seen hard times over the years. Neighbors said it is the kind of place where people can still be seen shooting heroin in the stairwells.
Monsegur's family was a subject of a 2007 story by The New York Times about former residents of public housing, barred from visiting relatives still living in the buildings because of drug convictions. In the article, Monsegur's father, also named Hector, said he wasn't allowed to visit his mother at the Jacob Riis Houses because he had served seven years in prison for selling heroin.
"The courts let me do seven, but with them, it's one strike and they give me life," he said.
Monsegur's Internet alter-ego was intermittently in contact with the press. Sabu once feuded furiously with Guardian journalist Charles Arthur on Twitter, and, in an account published Tuesday, Gawker journalist Adrian Chen said he'd even reached the hacker over the phone last September, describing him as having a thick New York accent and laughing off the threat of prison.
"I come from the streets," Chen quoted him as saying. "I'm not scared of jail."
Late last year, Sabu participated in a marathon question-and-answer session on user-driven news website Reddit. Among the Redditors' most popular questions: Have you been contacted by the government?
"No, not yet," Sabu replied. "I represent an idea, even if they do contact me they cannot stop that idea from moving forward."
Elsewhere he identified himself as a "grown ass man" from the Bronx, said he had a background in English and social sciences, was an Eagles fan and a self-taught hacker. He said he liked writing, playing music and "spending time with family." He said he was a car buff, too.
Federal prosecutors confirmed that much in an indictment unsealed Tuesday, saying that Monsegur had hacked into the computer systems of an auto parts supplier and shipped himself four motors, worth $3,450.
Sabu's politics were a matter of speculation. His Twitter avatar used to display the green Sha'ada flag often used by Hamas. Sabu described himself as an anarchist sympathizer who got involved in the loosely organized worldwide hacking group Anonymous when Pfc. Bradley Manning, accused of engineering the biggest leak of classified information in U.S. history, was arrested. Sabu called the jailed American private, whose defense lawyers say he was emotionally troubled and shouldn't have had access to classified material, "my overlord."
Asked if he was afraid of being caught, he replied: "I'm past the point of no return."
In one exchange, Sabu was asked if he had any advice for new hackers.
"Stick to yourselves. If you are in a crew - keep your opsec (operations security) up 24/7," he advised. "Friends will try to take you down if they have to."
Explore further: Authorities: Hackers busted when 1 turns informant (Update 2)