In the 1990s, researchers Melissa Farley and Howard Barkan conducted a study on prostitution, violence against women and post traumatic stress disorder, interviewing 130 San Francisco prostitutes. Their findings indicate assault and rape are all too commonplace:
Eighty-two percent of these respondents reported having been physically assaulted since entering prostitution. Of those who had been physically assaulted, 55% had been assaulted by customers. Eighty-eight percent had been physically threatened while in prostitution, and 83% had been physically threatened with a weapon….Sixty-eight percent…reported having been raped since entering prostitution. Forty-eight percent had been raped more than five times. Forty-six percent of those who reported rapes stated that they had been raped by customers."