In the improbable case of a set of parents willingly allowing their 10 year old child to be sexually exploited, social ostracization would possibly remedy their poor decision regarding their child much more quickly than some government law. Besides, relying on government to "rescue" the child would hardly be an improvement, since the government would practice its own version of molestation on the child.
I live in a society in which people consider government to be necessary, and I understand the emotional appeal of having the government set up laws to apprehend and punish child molesters; they violate the rights of the innocent and defenseless, which makes their activity particularly abhorrent. With this in mind, punishing child molesters seems to be one of the few legitimate functions of government. Caution should be used, however, as government laws can unfortunately backfire occasionally, and result in truly innocent people being wrongly punished for reasons of political advantage or personal animosity: http://www.criminalattorney.com/news/child-molestation/
Social ostracization isn't as satisfying as the idea that the offender will be "strung up" (or whatever); it doesn't seem to be as powerful a deterrent as the idea of a S.W.A.T. team crashing through the front door with guns drawn. But when an individual finds that he cannot buy food from the local grocer, that his neighbors cut him off socially, that he cannot, in short, live as much as possible a normal life, then he must either move away or change his behavior.
The truly Christian thing to do (yes, I am one of those unintelligent believers in God, though I do not believe in Santa Clause--rather arbitrary, what?) would be to adopt the child from the bad parents, and trust to God's eventually punishing the offenders in the most God-awful way imaginable.