'Rain dancing 2.0': should humans be using tech to control the weather?

A cluster of new technologies aim to fulfill humanity's ancient desire to influence the weather. But is it a good idea?

Farmers in Mexico have accused Volkswagen of ruining their crops by installing "hail cannons", which fire shockwaves into the atmosphere in an effort to prevent hail storms from damaging the cars rolling off the production line.

The devices are being blamed for causing a drought during months when farmers near the German carmaker's plant in Puebla expected plenty of rain.