More than half the children in India are sexually abused, and 70% of this abuse went unreported [more on the statistic here]. Those who imagine that abuse is confined to a particular stratum of society would be well advised to consider the fact that children are powerless people, regardless of their family's social status.
Child abusers emotionally abuse and entrap children in a private fear-filled world by highlighting their powerlessness and demonstrating to them that they have no place to run to. Taboos and notions of shame are likely to excarbate a situation where the child feels unable to tell anyone about sustained abuse. Being silenced everytime he/ she attempts to bring up anything related to sex can hardly be constructive in such a situation.
Despite the appalling statistics and the undeniable violence and damage caused to children who cannot understand or speak of their experience, sex education is seen as undesirable by many. States in India are actually going to the extent of banning sex education.