Someone on this list said that legal threats are just another type of, or another name for, or a euphemism for, personal attacks.
You are incorrect. There is a humongous difference, even though it's easy to draw a parallel.
The difference between personal attacks and legal threats is the difference between "I hate you because you're an evil idiot who eats babies" and "I am going to break your leg and stab you in the arm tomorrow behind the supermarket."
I do not believe there should be any tolerance whatsoever for legal threats. Personal attacks and other mere arguments may be offencive, but that's all just a part of the debate of Wikipedia, even if it's a rough part of debate and one to avoid.
Legal threats are an entirely different thing. If the policy does not provide for it now, any user making a serious legal threat should be blocked on the spot, I believe. Forever. --
DOMINGO GALDóS