A security guard checks chairman of Lone Star, John Grayken (C) as he arrives at a local court in Seoul January 11, 2008. South Korea's prosecutors have banned the U.S. private equity house Lone Star's chairman from leaving the country for 10 days as he testifies in a local court to defend the head of its Korean operations, a newspaper said on Thursday. REUTERS/Han Jae-Ho (SOUTH KOREA)