Threat Matrix: July 2007 June 2007 Threat Matrix Index Theat Matrix Handbook Theat Matrix 'BOLO' Invaluable Tips Preparedness US Steps Up Security Following Attack in Britain Homeland Security Secretary Michael Chertoff made appearances on several television talk shows. He told ABC's This Week program there is no indication of a linkage between the events in Britain and any specific attacks on the United States. "We do not have, at this point, specific, credible intelligence that there is an attack, a particular attack, focused on this country," he said. But at the same time, speaking on CNN's Late Edition program,...