"Espionage acts can include stealing documents, listening to private communications, hacking computer systems, or recruiting insiders to share classified information. While spying is sometimes viewed as necessary for national security, it is also considered illegal and dangerous in many countries. As technology has evolved, so has espionage. Today, modern espionage can include hacking computer systems to steal corporate trade secrets, using cell phones to intercept classified conversations, or infiltrating organizations to copy cutting-edge scientific research. Espionage remains a powerful tool for global competition in the modern world, and it does not appear to be slowing down"-- Provided by publisher.
Spycraft : The History of Espionage