Rape culture is "a complex of beliefs that encourages male sexual aggression and supports violence against women.... A rape culture condones physical and emotional terrorism against women as the norm" (Transforming a Rape Culture by Buchwald, Fletcher and Roth).
An example of this can be found in the 1984 movie Sixteen Candles, starring Molly Ringwald, Anthony Michael Hall, and Michael Schoeffling. Ringwald plays Samantha Baker, and most of the action is set on her 16th birthday. She has a crush on Jake (Schoeffling), but Farmer Ted a.k.a. the Geek (Hall) is the one who keeps hitting on her. The scene below, which occurs on the bus ride home, seemed harmless to me when I was a teen but is shocking now:
Although Sam tells him that he isn't welcome, Farmer Ted sits down next to her with one arm on the seat behind her and the other on the seat in front, partially encircling her and invading her space. He stays there, in her space, close to her body, even pausing a moment to smell her neck. When she insults him, he's offended and criticizes her manners.
This is rape culture. It never occurs to her to yell for help, to yell at him to get out of her face, or even to change seats. Rape culture supports the idea that this is what women are expected to endure. The Geek's fault isn't that he's coming on to her; it's his lack of social graces and his refusal to recognize her rejection.
It gets far, far worse. During a wild party at Jake's house, his girlfriend Caroline passes out. Jake says he could "violate her ten different ways if I wanted to." The Geek replies, "What are you waiting for?!" Jake allows the Geek to drive Caroline home in his car. On the way, the Geek stops at his friends' house so they can take a picture (this was long before the days of cell cameras). He manipulates her body so that she is partially sitting in his lap. The next morning, the two wake up in Jake's car. Caroline believes she and Ted had sex (i.e. date rape, since there's no way she could've consented), but she's okay with it.
I used to believe that Caroline was imagining this and that Ted would never do that to her. He seems such a good guy! I was so naïve. Ted had already shown that he believes girls owe him sex. He's confused that Jake would not want to rape Caroline if he has a chance--that's what women are for. Who knows what other photos were taken after the initial one? What advantage was taken of her body? Caroline is defined in terms of her sexual availability. Her body is freely available to be used and manipulated. And in the end, it doesn't even bother her. Because THIS IS THE NORM.
And that's what rape culture means. It's the expectation that men will rape women if they can and that women make far too big a deal out of it, because it's really just normal behavior and they can't help it.