In Pictures: 9 employee insiders who breached security

These disgruntled employees show what can happen when an employer wrongs them.

  • Security admins used to have to worry about keeping the bad guys out of the network, but there have been many documented cases where the devil you know is sitting right next to you. A review of recent FBI cyber investigations revealed victim businesses incur significant costs ranging from $5,000 to $3 million due to cyber incidents involving disgruntled or former employees, according to AlgoSec. Here are just a few over the years of insiders trying to take down their employer's network.

  • Terry Childs, the former network administrator for the City of San Francisco, held the city's systems hostage for a time. He refused to surrender passwords because he felt his supervisors were incompetent. Childs was convicted of violating California's computer crime laws in April 2010.

  • In June 2012, Ricky Joe Mitchell of Charleston, W.Va., a former network engineer for oil and gas company EnerVest, was sentenced to prison for sabotaging the company's systems. He found out he was going to be fired and decided to reset the company's servers to their original factory settings.

  • It was discovered in 2007 that database administrator William Sullivan had stolen 3.2 million customer records including credit card, banking and personal information from Fidelity National Information Services. Sullivan agreed to plead guilty to federal fraud charges and was sentenced to four years and nine months in prison and ordered to pay a $3.2 million fine.

  • Flowers Hospital had an insider data breach that occurred from June 2013 to February 2014 when one of its employees stole forms containing patient information and possibly used the stolen information to file fraudulent income tax returns.

  • According to, 34-year-old Sam Chihlung Yin created a fake VPN token in the name of a non-existent employee which he tricked Gucci IT staff into activating after he was fired in May 2010.

  • Army Private First Class Bradley Manning released sensitive military documents to WikiLeaks in 2009. Manning, now known as Chelsea Manning, was given a sentence of 35 years in prison.

  • Back in 2002, Timothy Lloyd was sentenced to three-and-a-half years in prison for planting a software time bomb after he became disgruntled with his employer Omega. The result of the software sabotage was the loss of millions of dollars to the company and the loss of 80 jobs.

  • Earlier this year, NRAD Medical Associates discovered that an employee radiologist had accessed and acquired protected health information from NRAD’s billing systems without authorization. The breach was estimated to be 97,000 records of patient names and addresses, dates of birth, Social Security information, health insurance, and diagnosis information.

  • And of course there is the most famous whistleblower of all time: Edward Snowden. Before fleeing the country, he released sensitive NSA documents that became a blowup about government surveillance.

Show Comments