Spying is sometimes called "the great game." Billions of dollars, state security, and sometimes even lives, are at stake. In the new book "Nest of Spies: The startling truth about foreign agents at work within Canada's borders,” authors Fabrice de Pierrebourg and Michel Juneau-Katsuya say Canada is often a prime target. Marc Montgomery speaks with Michel Juneau-Katsuya about how spying has changed in the 21st century and what's at stake for Canada.