When Home Depot suffered a breach of transaction data that exposed as many as 52 million credit card transactions earlier this year, the company reportedly suffered from lax computer and network security measures for years. Apparently, the company wasn’t helped much by its selection of a security architect either. Ricky Joe Mitchell was hired by Home Depot in 2012, and in March of 2013, he was promoted to the position of Senior Architect for IT Security at Home Depot, in charge of the entire company’s security architecture. In May of 2014, Mitchell was convicted of sabotaging the network of his former employer.

Further Reading Home Depot ignored security warnings for years, employees say

When Mitchell learned he was going to be fired in June of 2012 from the oil and gas company EnerVest Operating , he “remotely accessed EnerVest’s computer systems and reset the company’s network servers to factory settings, essentially eliminating access to all the company’s data and applications for its eastern United States operations,” a Department of Justice spokesperson wrote in a release on his conviction. “Before his access to EnerVest’s offices could be terminated, Mitchell entered the office after business hours, disconnected critical pieces of…network equipment, and disabled the equipment’s cooling system.” As a result of his actions, the company permanently lost some of its data and spent hundreds of thousands of dollars repairing equipment and recovering historical data. It took a month to bring the company’s office back online, costing the company as much as $1 million in lost business.

And that wasn’t the first time he used technology for revenge. Mitchell’s previous legal troubles resulting from malicious use of his technical skills dates back to when he was a high school junior. In 1996, at the age of 17, Mitchell—who then went by the handle “RickDogg” in online forums—planted viruses in his high school’s computer system. He was suspended for three days from Capital High School for planting 108 computer viruses “to disk space… assigned to another student on the Capital High School computer system,” according to a school district memo obtained by the Charleston Gazette. He then posted threats to students whom he blamed for reporting him. Mitchell was expelled from the school and sued to be re-instated. The case eventually went to the West Virginia Supreme Court.

On his 1996 personal website, Mitchell posted a description of himself with the title, “The story of RICKDOGG”:

I love to write and distribute Viruses. They intrigue me. I have taught myself how to program in assembly, c- - and pascal. I also love to fix computers as well. I am considered smart at school although I am very lazy. I do not like the shit they try to teach me so I get bored and try to liven things up a bit.

As Ars reported earlier, former Home Depot employees told the The New York Times they were not surprised by the hack. When they requested additional security training and equipment, managers denied the request with the explanation, "We sell hammers.”