From the NRO:
Pre-feminist common sense suggested that a woman who comes alone to a man's hotel room late at night has already consented to sex with him, but on the all-or-nothing principle so dear to ideologues everywhere, feminist orthodoxy insists that the adoption of this rough-and-ready but extremely useful guide would be tantamount to saying that a woman who has slept with other men not her husband, or even who dresses provocatively has already consented to sex. And the feminist interpretation of the law is now almost uncontested in the courts. No means no — even though no one else hears it, even though everyone knows that it may mean yes — because feminists want to reserve to women the right and freedom to be indiscrete.
Well, even the liberal Gregg Easterbrook doesn't think "no" should mean "no," though I don't think he quite went as far as endorsing "crossing the hotel room threshold means you give up any say about what happens to you" standard.
(link thanks to JE)