Person A does Act B to Person C. The law says this is a crime.
If Person C is a minor, Act B is no longer a crime.
What are the arguments for and against this kind of legal / social arrangement?
I instinctively feel the law should be giving more protection, not less, to children than adults, but we find this not so in practice.
UPDATE
OK, so people want examples:
A
If Adult A strikes Adult B with the open hand, this is the crime of assault. Adult A can be arrested.
If Adult A strikes Child C with the open hand, this is not assault. Adult A would not be arrested.
B
If Adult A ties down Adult B by the arms and legs, naked and spread-eagled, and uses sharp implements to cut off a part of his penis, that is sexual assault and battery causing grievous bodily harm.
Id Adult A ties down Child B by the arms and legs, naked and spread-eagled, and uses sharp implements to cut off a part of his penis, with no medical benefit, this is considered OK.