From CSWiki
I don't know whether or not this is apocryphal, but it's too good a story not to repeat.
Jochen.Fromm, who has a nice
Complex Adaptive Systems page, writes about
a funny story our professor has told us. The government in India long ago tried to prevent the spreading of a snake plague, so they offered a high reward for every snake that would be catched. The result was that the people started to breed snakes in farms in order to make a lot of money.
It's so simple isn't it. Offer money for snakes, and people will find ways to supply them.