Women have a right to dress any way they wish. It is the rapist who decides to force sex on the victim. The rapist looks for a woman who is accessible and vulnerable, not one who is sexy. Oh, she sleeps around. Statements such as these put the blame on the victim and not on the offender.
Rape is never the victim's fault.
Even if she did something that puts her in a vulnerable position, she did not ask to be sexually assaulted. It's not as traumatic to be raped by someone you know. Just because the victim knows the rapist doesn't make it any less a crime or any easier to deal with. Often the emotional impact of acquaintance rape seems greater than that of stranger rape. Also, the victim may have a strong feeling that no one will believe her.