British security officials confirmed Thursday that the suspects were known to MI5, the domestic security agency, in the years before the attack, which stunned many people with its sheer brutality.  http://www.nytimes.com/2013/05/25/world/europe/london-attack.html?pagewanted=1&src=twr    What British security officials knew about the two men held after the London attack remained unclear. But unidentified officials who spoke with British reporters […]