Spoiler - did Daniel?
Arrange the 'abduction', so he could have sex with his sister?
If this was alleged in the movie, then sorry I missed it.
An earlier thread discusses this idea. http://www.imdb.com/title/tt1392888/board/nest/173818097
I think there's a little wiggle room that could allow you to get the impression that Daniel was involved in the abductions but I think it falls apart as he falls apart during the rest of the movie.
This movie is pretty straight forward: kids get kidnapped, forced to have sex, deal with aftermath. I don't think it was supposed to raise any questions about who and why kidnapped Daniel and Ana.
I agree.
I think this movie just frustrates people because it could have been much better than it is so they start looking for more twists to go with the bizarreness of the majority of the stuff that happens after the kidnapping.
True.
Now days viewers just expect some twists and turns in movies to keep them entertained. But this film is a pshycological drama about how families get torn apart after a realy big tragedy. It shows us how fragile our minds are, how easy it is to break us and make us do horrible things. And how despite everything we are still able to hurt people we love and who love us.