I realize these decisions are hard to make on the spot, but it's important to grab everybody and pull them out on the spot. As a teacher (or me in a previous life, as a manager --- also of adults), when you disagree very strongly with the ethics of actions of others, I found it both personally and team-wise rewarding to react decisively in front of my team so they'd get the message.

This applies to not only strange security, but harassment, unethical behavior, and other inappropriate actions.

Trust me from personal experience, you'll never regret it, and as you get older, the retelling will only get _more_ enjoyable, both for you and those who were there to see you blow up. On both sides, so long as you keep it professional.