I'm not liking this word that has gained currency.
I think we should be writing something like "extralegal paramilitary" or "extralegal Basiji", to emphasize the sketchy legal foundations of their actions.
In fact, I think this angle is what ought to be used by our Secretary of State, when leveling criticisms. How shameful is it that the Islamic Republic of Iran has to rely on the un-uniformed and unidentifiable to maintain/enforce its legitimacy?