Nicknamed “No Such Agency” and “Never Say Anything” for its legendary secrecy, the National Security Agency conceals its headquarters behind tall fences topped with barbed wire. Its employees are in the business of breaking codes, eavesdropping and guarding secrets. And its normally reticent leaders rarely call attention to themselves outside the agency’s sprawling campus. So it was an extraordinary event when some of the agency’s top officials emerged in Annapolis about a year ago at the opening of a business center dedicated to helping start-up homeland security companies.Full Story