When Slutwalkers paraded bare-breasted on the streets of many cities,  focusing on unclothed or barely dressed  women not inviting rape, they should have been protesting that rape was being under reported because of an archaic definition of sexual assault used by the Federal Bureau of Investigation (FBI) that was created over 80 years ago.

At that time, the FBI defined rape as the ‘carnal knowledge of a female, forcibly and against her will’, a term narrower than that used by most…