Speaking as someone who has been on a security team for conventions in the past, this is a sadly common thought. "Someone is doing something that makes me feel unsafe, but I don't want to 'ruin everyone else's fun' so I'll be quiet" is exactly how countless people feel before real tragedies happen.

On the other hand, people who had this same feeling and decided to let security know anyway have stopped or cut short even more tragedies. So, on behalf of every security team at every con ever: If you see something that makes you feel unsafe, find us and let us know about it. It may save lives.