Fireworks and child labour
In India, there is a festival called Diwali when everyone lights fireworks. Its called the "festival of lights" and every home is decorated with dozens of candles on the outside. All the cities look very pretty and everybody is dressed in new clothes. Its a happy day.
The fireworks that are set off on Diwali are mostly manufactured in small scale "home factories" in the state of Kerala. There are thousands of such homes and the work force consists of children sometimes as young as six. It is dangerous work and there have been accidents.
In an attempt to discourage child labour, all the affluent schools of Delhi told their students not to set off fireworks on Diwali. The children took this seriously and tried their best to dissuade everyone from using fireworks.
The only problem is that the poor children of Kerala got paid even less because of the drop in sales of fireworks. They ate even less than their usual meagre amounts. Their tormentors treated them ever more badly.
All this while the cities felt good about how they were helping eradicate child labour!