Yeah, I really feel sad when I see those articles and comments telling you not to share anything that you don't want your boss to know with your colleagues, or even better ignore them completely and automatically treat as deadly competition. If you cannot trust anybody and have difficulties with assessing if someone won't turn his back on you, it may be a problem with your social skills, not with other people.

This kind of thinking encourages situations where the employer may have total control over his employees, like with Amazon.