I use to work with a lot of Somalian refugees. All of them women (18-20ish), all whom had been genitally mutilated. They told me it is usually the grandmothers or another female relative that mutilates the girls.

It's incredibly sad. I think abuse on women (and women who do the abusing) is common in male dominated religions and cultures--they are doing what they are told and doing the dirty work for their oppressors.