This Time.com article describes "purity balls," at which fathers take daughters and pledge to keep their daughters pure (abstinent) until marriage. These fathers probably have the best intentions, and I believe in the importance of fathers in daughters' lives. If daughters feel loved and respected by their fathers, they're more likely to date guys who love and respect them.
But, if the goal is to prevent sex before marriage, why are they only focusing on the girls? It takes two to tango, you know.