A teenage Welsh hacker at the centre of a multi-million pound FBI fraud investigation has been sentenced to three years of community rehabilitation with psychiatric care for what the defence called an obsessive medical condition. Raphael Gray, a 19-year-old from Clynderwen in West Wales, called himself the "Saint of E-Commerce", and said he was on a mission to highlight security dangers on the Internet. The only problem was that to do this, he cracked thousands of computer networks and gained access to more than 23,000 credit card numbers. He posted thousands of the numbers on the Web, leading to roughly $2.8m (about £4m) in fraudulent credit card charges and causing two companies to close down. His best-known stunt, however, was to use Bill Gates' own credit card number to mail-order the Microsoft chairman a large shipment of Viagra. Gray's crusade brought him to the attention of the FBI, who were "greatly troubled by his disturbed crusade", according to prosecuting lawyer Leighton Davies. Gray admitted to stealing credit card information from sites including feelgoodfalls.com, mostorefront.com, albionsmo.com and the American Society of Clinical Pathologists' Web site. The teenager had previously pleaded not guilty to charges of breaking section 10 of the Computer Misuse Act -- legislation designed to combat computer crime -- by downloading unauthorised material. Colin Nicholls QC, defending, said that Gray suffered from a medical condition that made community rehabilitation necessary. "He was obsessed by his crusade -- he is a highly-strung man going through an abnormal period in his life," Nicholls said. Will Knight contributed to this report. Is your PC safe? Find out in ZDNet UK's Viruses and Hacking News Section. Have your say instantly, and see what others have said. Click on the TalkBack button and go to the Security forum. Let the editors know what you think in the Mailroom. And read other letters.