Terry Childs was the principal network engineer for the Department of Telecommunications and Information Services of the City and County of San Francisco. He set up the city's computer system where he was the only person with access to the network's passwords. When he was suspended from his job, he refused to divulge the passwords for 12 days. A court of appeals upheld his conviction for hoarding passwords (California Penal Code § 502(c)(5)) by holding,
he knowingly prevented the city from being able to use its own computer system for a time, deliberately configured that system so that no one else could access it, set it up so that anyone other than him attempting to enter it would erase the data stored in it, and made the network more vulnerable to external attack by the filing of an unauthorized copyright application.
He had been sentenced to four years in prison, and ordered to pay $1.5 million in restitution.
Read about it in Forbes.