The world knows the name Edward Snowden. He was the man who leaked highly classified documents from our nation$$s National Security Agency $($NSA$)$ and ended up fleeing to Russia. It was reported that Snowden persuaded $2025$ co$-$workers to give him their login credentials by telling them he needed them to do his job. This gave him greater access to the NSA's computer system. That is how he had access to all the documents he leaked. What cybersecurity design principle$($s$)$ could have helped prevent his espionage activities?