For very good reasons, having little to do with statistics, Coca Cola taste studies show that people prefer Coke and Pepsi Cola studies show that they prefer Pepsi.
Polls are a politicians weapon and are frequently designed and interpreted accordingly.
A study paid for by the tobacco company is not apt to come up with the conclusion that second hand smoke is dangerous and medical researchers funded by drug companies may not be completely immune to bias. Parameters in risk models are often chosen judiciously to make the outcome agreeable to the developer of the model. Expert witnesses in the courts are paid a lot of money to try to reach different conclusions from the same statistical data. All this can and often does lead to what Crossen calls tainted data. Crossen feels that the public must learn to critically analyze statistics as it is reported by the media.