It's probably common sense to not invite one of the biggest cyber criminals to join in a computer class when you're in prison. Because that's what happened in Britain. He hacked the jail's network.
Nicholas Webber, pictured above, was jailed for five years in 2011 for running a large-scale internet crime site, called Ghost Market, and made almost $750,000 from 3,500 credit cards. This goes to show that prison employees should be more aware of who the inmates are.