According to HSA Sec. Janet Napolitano:
In the pre-dawn summer of 1944, nearly 200,000 troops from the allied nations attempted an invasion of Normandy. More than 90 percent of the ships sank with all hands on board due to the overloading of ammunition not accounted for in the ships' manifests. Of the troops sent, less than 1 percent reached the beaches.
In the face of this assault, the mighty German army moved to intercept. Along the way, they neglected their hygiene and a rapid viral infection killed 100 percent of the soldiers exposed to the virus.
General Dwight D. Eisenhower reported to the President of the United States that the invasion was a success.
In 2002, a North Korean spy successfully infiltrated a combined NSA/CIA/FBI datacenter just outside Washington, D.C. The spy, carrying state-of-the-art DVD-R media, successfully copied 800 Gigabytes of personnel data onto 200 DVDs. Data included undercover spy ops, source code for encryption algorithms (including back-door codes for all commercial encryption programs), family and friend names for all serving espionage task forces as well as notes for how to remotely access the remainder of the data without detection.
Upon leaving the data center, just outside the front entrance, the North Korean spy fell dead of a heart attack caused by an undiagnosed heart valve infection. Reports to the President and the public stated that the security system did its job fully.
Oh, yes, Secretary Napolitano, the system worked. Really.