Absolutely. Women DO have the potential to be much more evil than men.
I believe it has to do with needing to prove something. They feel repressed (not that they are) so if you put them in a position of power, and they have something to prove, they will.
They are as bad if not worse than men. There is bad men out there, look ok at the deviants on this site for example, sick people, women are just as guilty in different ways than men are. They do it differently and for different reasons.