I was with a friend who was at a very high clearance level. He opened his briefcase once and went pale. He inadvertently brought a classified document home. He stopped our conversation and locked it in his safe then told me he’d report himself in the morning.
In 1995, before we were married, my husband was at my place for dinner. He had TS clearance.
My phone rang, and it was a woman asking for him. A few seconds into the conversation he went pale, and yelled, “This conversation is over!” and slammed down the receiver. He called his boss at home and reported it immediately. Then there were reports, forms, etc., to be done at the office.
Allegedly, she was a writer and wanted info on procedure or policy, and she knew stuff she absolutely should not have. (And how the hell did she get MY phone number?)