If there really are Purity Balls, even remotely like what Morford is suggesting, that is wacky.
My daughter along with lots of others teens at our church walked up to the front of the sanctuary and vowed to remain sexually pure until she was married. The congregation said a prayer for them and they returned to their seats. The young man she married in January had done the same so they made sure they were never alone in compromising situations before they married. They courted, rather than dated. That meant having someone chaperone from time to time which was sometimes inconvenient for the moms, but we did what we could to help them, as good parents do.
Both say they are glad they waited for one another.
Actually, this is simply harnessing the power of positive peer pressure, as well as celebrating chastity. I fail to see anything wrong with it.
"Purity Balls" - isn't that the painful condition that guys experience when girls won't sleep with them? :)