Oh yeah I was staying silent in many situations. When I was "questioned", remaining silent never occurred to me as an option. The issue was that I was generally nervous in many social situations due to my stuttering. I guess I had a certain he's hiding something vibe for some people. Once I was accused, I was more nervous in the next similar situation, and the spiral goes on and on, as it often does with such things. Security guards, police officers, border guards are especially sensitive to and are often looking for nervousness. Me looking visibly nervous when I saw police, border guards, etc. certainly didn't help me not to look suspicious to them :D