Dariusz J. Prugar, 32, of Syracuse, New York, has been sentenced to two years in prison for hacking his former employee, Pa Online, an internet service provider. He used his old credentials to log into the ISP’s network, install backdoors, and retrieve scripts and software he worked on during his employment at the company. The ISP’s systems crashed, affecting over 500 businesses and over 5,000 residential customers. The outage lasted for a week, during which time the ISP lost multiple clients, and took serious damage to its reputation.
Source: https://www.bleepingcomputer.com/news/security/sysadmin-gets-two-years-in-prison-for-sabotaging-isp/