Today, much like christianity's idea of biting forbidden fruit, opening pandora's box refers to getting into a situation over which one has very little control over.
Other Guy : " That stank ho? You don't wanna mess with her; personally, I wouldn't touch her with a nine and a half inch pole."
Guy : " Why?"
Other Guy : " Dude, she's got Pandora's Box."
Guy : "Oh sick! Someone get hazmat."