NYT: "Britain's most powerful counterterrorism officer resigned on Thursday, a day after being photographed carrying a document that outlined details of a major antiterrorism operation in northwest England and was clearly marked 'Secret....' The airing of the document, visible to waiting reporters and photographers as [the officer] walked to Downing Street for a security briefing, provoked a hasty flurry of arrests and raids on properties by hundreds of antiterrorism officers around Manchester, Liverpool and Lancashire late on Wednesday."