style="overflow: hidden; color: #000000; background-color: #ffffff; text-align: left; text-decoration: none; border: medium none;">In 2009, engineers at Google claimed they could predict the progress of flu epidemics simply by looking at the words people were typing into their browsers. The idea was both plausible and ingenious; since Google services 3bn search queries every day, the company is quite capable of tracking how often people are asking about flu symptoms or medicine.