"There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know."

Researchers at the University of Pennsylvania say they've discovered a way to circumvent the networking technology used by law enforcement to tap phone lines in the U.S.

The U.K. government said Monday it plans to push for a law requiring service providers such as ISPs to retain data about instant messages, e-mail and other electronic communications.

Criminal arrests made under more powerful wiretapping laws have increase by 96 percent following reforms that make it easier for police to intercept and access telecommunications.

They sometimes call national security the third rail of politics. Touch it and, politically, you're dead.