St. Pancras Medical Center, an acute-care hospital, issued a memorandum prohibiting its nursing and patient-care employees from wearing buttons that read: “RNs Organized to Promote Patient Care.” The buttons were an effort to show support for the nurses’ union in contract negotiations with the hospital. The hospital directed the employees not to wear any buttons in any patient-care areas and anywhere they might meet members of a patient’s family. The hospital claimed that wearing the buttons could cause “unease and worry among patients and their families,” and disturb the tranquil hospital atmosphere that is necessary for successful patient care. The Union feels that the rule is overly restrictive and filed an unfair labor practice charge with the NLRB. Does the rule violate the NLRA? Explain your position?