If it is hearsay, we have to ask who is spreading this misinformation and what their goal is. I haven't heard of any. I think we need to know the facts in these areas. As an UPTE member, I have threatened no one and am not prone to physical violence. Nor do I know of any physical violence or destruction of property that has occurred during UPTE elections anywhere.
Unions are democratic.
Extortion is not legal. Work stoppages and disruptions of vital services have been used by unions, but these are governed by law. Recently, though, there was a strike at the University of California. It was by the graduate student assistants who UC would not allow to unionize. After years of legal battles and a strike, the graduate student assistants finally won the right to collective bargaining.