Even though the court documents unsealed this week had revealed that the 28-year-old shadowy Internet personality `Sabu' - `Anonymous' informant Hector Xavier Monsegur - was a chronic lawbreaker, his pleading guilty to 12 computer hacking crimes, has prompted the federal prosecutors not to charge him with an array of other crimes.

Going by the court documents which have recently been made public, `Sabu' - who became an FBI informant last year - had a pretty notorious background. Along with his involvement in hacking activities, he also dealt drugs, used marijuana, and possessed an illegal handgun.

However, ever since his cooperation agreement with the federal prosecutors in Manhattan in August last year, Monsegur not only copped to the array of crimes he was involved in, but also admitted that a gang leader of the `Anonymous' hacking group, and has spearheaded the hack of government and business computers around the world.

Working from his six-floor apartment in the Jacob Riis Houses, New York City, Monsegur helped the FBI nab five of his Anonymous associates - from Ireland, Great Britain and Chicago - who allegedly had a hand in the hacking activities of the group.

In the wake of the help Monsegur - who is scheduled to male his forst court appearance on March 12 - extended to the authorities for locking up fellow hackers, federal prosecutors have decided against his prosecution for a litany of other crimes he admitted to have committed.