The late FBI agent-turned traitor left a strange mark in the annals of espionage
I used to think the CIA was a bit lax in its enforcement of the need-to-know principle. Then I learned what lax was, specifically how widely known within the FBI were the identity and activities of one of its most sensitive Soviet sources. This was before we had heard of Hanssen or Ames. Don't know if things have changed.
In 1975 I left "the circus" and Vietnam and went to "library school." Time to be useful. But when I learned about Hanssen I was amazed at the access he had to so many projects. Didn't they practice "need to know?" Perhaps they did. But his range of information amazed me. It sounded like everyone got together and boasted about their contacts. I never did that. I do hope things have changed.