Thank goodness I have sons. I'll never need to promise “before God to cover my daughter as her authority and protection in the area of purity” at a "purity ball."
More seriously, I think it's the responsibility of every parent, of both sons and daughters, to model responsible, honest, and respectful romantic relationships. The sad thing about abstinence pledges, or the pledges of fathers to protect their daughters "from 'hook-up' culture," are that they outsource a parent's responsibility. Would these fathers need the big production of a ball if they were simply straightforward and available for their daughters? Most of them probably work too damn much to even know if their daughter is out fucking around (the ball costs $10,000), much less have the time to communicate frequently. They are examples of parenting failures.