FBI Most Wanted Hacker Jeremy Hammond Used His Cat's Name for Password Jeremy Hammond is serving a 10-year sentence for cyber crimes.

 -- A notorious hacker serving a federal prison sentence revealed that a weak password -- his cat's name -- may have led to his downfall.

Jeremy Hammond, who is serving a 10-year prison sentence for his role in cyber attacks against a private defense firm, law enforcement agencies and what prosecutors called "thousands of innocent individuals," was able to hack into systems that may have seemed impenetrable to others.

It would be fair to expect a hacker as skilled as Hammond to keep his private information carefully protected, but instead he told the Associated Press he used a password that was surprisingly easy: Chewy 123.

"My password was really weak," he told the AP.

Hammond said he still isn't sure how federal authorities were able to get into his encryption program and gather evidence that ultimately sent him to prison, however, he said he wonders if his weak password may have been the culprit.

The "hacktivist" portrayed his actions as acts of civil disobedience, but at his sentencing last year Judge Loretta Preska of the U.S. District Court for the Southern District of New York said Hammond "hacked into websites he disagreed with politically."