There is no agreement on what, if anything, constitutes an appropriate target for espionage.

After it was accused of espionage and spent a day in Egyptian detention , he was released in to a protectorate to fly free only to meet its end !!

The documents revealed by Edward Snowden indicate that they have implemented and even subverted Internet technologies for spying on a global scale, not so much for the anti terrorism fight as for commercial espionage.

Cuban Missile Crisis On October 14, 1962, CIA U 2 spy planes took photographs of intermediate range ballistic missile sites being built in Cuba by the Soviets.

We cannot turn the other cheek pretending that it is not scientists and engineers who develop technologies that are later used to spy on billions of citizens or kill civilians by remote control.