As a non-JW, but having been influenced by my Dad who was a non-baptized publisher for years, I refused to sign to join our teacher's union although it was considered mandatory. The union seemed unaware of this omission and took my dues monthly, issued me a union card anyway and allowed me to benefit from the lower group insurances.
When the call came to strike I stayed home but did not join the picket line. When the government ordered the union back to work they defied the order. I went in to work. I had placed a note in each teacher's box informing them that as a Christian I am a man under authority and the authority of the government is greater than that of the union. I promised to donate any salary I received while the strike continued.
When it was over, I had a few haters, but most understood. The union rep wanted me to donate my salary to the union; I had already donated it to organizations such as World Vision. They actually demanded to see the receipts which I gladly showed them.
I have found that both unions and management/government can be unreasonable