A former U.S. National Security Agency contractor has been sentenced to nine years in prison as part of a plea agreement after pleading guilty to one charge of stealing a classified document in March.

Harold T. Martin III was arrested in August 2016 and was found in possession of 50 terabytes of government data, including documents marked “Secret” and “Top Secret.” Initially charged with 20 separate offenses, each with a potential sentence of up to 10 years in prison, prosecutors dropped the other charges in return for the plea agreement.

It’s not the first case where an NSA contractor has stolen data, but Martin’s case was notable because he was charged not with sharing the documents with third parties but with willful retention of national defense information. Martin was, however, at one stage the prime suspect in leaks of NSA documents and spy tools that were obtained and published by The Shadow Brokers.

Martin, in effect, did nothing more than hoard secret NSA documents on his own computer, with his lawyers arguing that his motivation was to “improve his computer expertise.” That hoarding took place from the late 1990s through to his arrest in 2016 and involved 300 times the data stolen by Edward Snowden, CBS Baltimore reported Friday.

“My methods were wrong, illegal and highly questionable,” Martin told the court at the sentencing hearing.

“For nearly 20 years, Harold Martin betrayed the trust placed in him by stealing and retaining a vast quantity of highly classified national defense information entrusted to him,” U.S. Attorney Robert K. Hur said in a statement.  “This sentence, which is one of the longest ever imposed in this type of case, should serve as a warning that we will find and prosecute government employees and contractors who flagrantly violate their duty to protect classified materials.”

Martin’s story is a reminder to all companies of potential insider threats. Sai Chavali, security strategist at ObserveIT Ltd., previously told SiliconANGLE that “given the right motivations and circumstances, professionals, like Mr. Martin, can cause greater harm by exfiltrating and leaking data.”

Photo: NSA/Wikimedia Commons