Hard Candy with Patrick Wilson and Ellen Page. One creepy, intense movie that really got me riled. It's certainly suited to a debate, but not for a blind right/wrong debate with absolutist, sexist arguments. My personal opinion is that the girl is in dire need of a vacation, specifically one to a certain "Hostel" in Slovakia.
SPOILERS AHEAD
Now, the debate is: are the crimes committed by the man sufficiently atrocious to warrant the events in the movie? And are the events in the movie atrocious enough to warrant my suggested punishment? When dealing with this, it is important to only look at what was explicitly proven and stated in the film and not every single claim, allegation or suspicion the girl had. Now, the director is brilliant in only providing just enough solid proof to keep the plot from being completely ambiguous. All that we know about his secrets are from the reactions of a sadistic and legally insane character looking for anything that might prove her right. It's important to look at the movie in retrospect, seeing how carefully orchestrated and planned her whole scheme was and factor that into her character. But also remember that everything we learned at the end she knew for certain all along. That exonerates her only slightly, because it is inferred that she obtained all this information from the guy's friend using similar methods but operating on less than absolute certainty. He was a monster for his actions that were left unseen; she was a monster for her actions both seen and unseen. He deserved punishment, but is a monster who kills a monster any less monstrous?
And I'd also like to add that movies like this are what make being bound a borderline phobia of mine.