A Pennsylvania man pleaded guilty to installing backdoors on several government, university, telecoms, and commercial systems and offering access to them in exchange for payment. Among others, the man offered undercover agents access to U.S. Department of Energy supercomputers that he had compromised via universities that had access to them.
Source: http://news.softpedia.com/news/Hacker-Admits-Selling-Access-to-US-Energy-Department-Computers-378659.shtml