Let's say a Soviet exchange student back in the '70s would go back and tell the KGB about people and places and things that he'd seen and done and been involved with. This is not really espionage; there's no betrayal of trust.
Aldrich AmesMy little scam in April '85 went like this: Give me $50,000; here's some names of some people we've recruited.
Aldrich Ames