If your nurse manager did say that non signers of this poster would be "weeded out" then you and the other nurses that have been threatened by this nurse manager need to report the nurse manager to your senior management and demand that this managers behaviour/threats be addresses. The nurse manager should be removed from their postition and if the hospital does not address your concerns then begin legal action against the hospital for not addressing the issue. Obviously the more nurses that witness the threatening behaviour the better. Bottom line is no one can force you to sign anything. Threatening you for not signing is illegal and renders what you sign invalid. I would like to say that the nurses union would be an ally in this situation but I have witnessed first hand repeated inaction by the nursing union to complaints over work conditions and treatment of nurses.