The controversy over the National Security Agency's interception of domestic communications without court warrant is not the first time the government has tried to shield a new surveillance technique behind a cloak of secrecy.
I can vividly remember the highflying U-2 spy plane that Lockheed developed for the CIA, unknown to the public until the Russians shot one down on May 1, 1960, precipitating a crisis that sent Nikita Khrushchev storming out of his Paris summit meeting with President Eisenhower.
Later in the cold war, aerial intelligence was largely replaced by the intelligence satellite, which could be used not only for pictures of the ground but for other purposes like space-based radar. For a long time the existence of the spy satellites - even the name - was a deep secret. They were referred to in arms-control talks as "National Technical Means of Verification."
In the 1970s, the Navy used submarines to tap Soviet cables under the ice off Murmansk. It was done secretly, until the existence of the submarine program was betrayed to the Russians by a spy in the Navy.
The post-9/11 war against terror brought to light new forms of secret surveillance. One was the Total Information Awareness Office, operated by a hush-hush Pentagon agency that assembled and computerized every kind of data about suspects - from medical records to travel plans. The project was headed by retired Admiral John Poindexter. He resigned when someone let the cat out of the bag. He said he still thought his data-scanning system was a very good idea.
So now we have the NSA's program of assembling and analyzing huge volumes of telephone and Internet communications in the hope of forestalling a terrorist act. All this without a warrant from the special court established for that purpose.
President Bush's first impulse when the NSA program was uncovered was to announce that the eavesdropping program would continue. His second impulse was to order an investigation of who leaked the story to The New York Times.
Periodically, the government will establish some secret program that will sacrifice a measure of individual freedom to some notion of national security. Periodically, thanks perhaps to an outraged whistle-blower, the surveillance plan may be revealed. Periodically, the government will try to wreak vengeance on the one who told. And, life in this democracy will go on.
• Daniel Schorr is a senior news analyst at National Public Radio.