Industrial espionage comes in many forms; the most commonly seen is the surveillance type methods, usually seen in the secret spy books and television programs. However, the truth is far from the glamour of the fictitious man who find out about the wrong, puts it right and gets the girl. In the real world this problem is a very real thing and one of the worst types of industrial espionage is the selling of trade secrets.
But this is only one cell of a much bigger definition, in recent years the definition of what is seen as industrial espionage has increased to cover such areas as; attempts to sabotage a corporation, in some cases, malware and spyware has even entered the arena of corporate espionage. And as earlier mentioned there are the more obvious kinds of industrial espionage such as theft of trade secrets, bribery, blackmail, and technological surveillance. more
Keep all this in mind when you suspect business espionage. The attack vectors are many; about half people, half technological. Solving the problem requires a holistic strategy, and working with specialists who have holistic mindsets. ~Kevin