Best female friends talk about their experiences, plans, desires, and fears. They also share distressing secrets and disturbing experiences. It is good to have someone in your life who knows, understands, appreciates, and respects you for who you are. But what if the friendship breaks up. All it takes is one careless word spoken at the wrong moment, or one fatal misunderstanding. Deep disappointment over a perceived betrayal of the illusion of deep friendship and of one's own feelings can trigger a cascade of seemingly justified (auto-)aggressive sanctions against the source of negative emotions through a sense of hurt that is perceived as devaluing, without discussion and clarification. Anything that has ever been disclosed in confidence will become part of the enemy's arsenal. Your former best friend and confidante knows all your sore spots. If she is unstable in character, or morally flexible, or insecure, or in some kind of dependency, or just not very smart, then you are really in great danger. You can be exposed and blackmailed by her at any time and in any form, lose your job, your career, your home, your possessions, your wealth, your friends, your reputation, your health, your freedom, your future, and even your life. All this because you have trusted and entrusted yourself without limits, and because trust is unfortunately fragile like thin glass. Privacy is a superpower. What others do not know about you, they cannot use to harm you one day. If you realize that few people are able to keep private knowledge that has been entrusted to them to themselves without using it against the source sooner or later, you should spare yourself the painful experience with this insight and not disclose private information unnecessarily.