I got this hilarious picture in my email (thanks Arns) which is a pretty cool example of what happens if you have a bad campaign and leave the window open for customer feedback. I mean seriously :) No driver likes it when cops are doing speed checks, and yes I know it is necessary but that is not the point in this discussion so put that thought aside for a second. In this example, the advertizer asks a question, and they give the consumer a large white space to answer that. No wonder some frustrated soul or practical joker gladly takes the opportunity to express his opinion. And then, yeah, this is what you get.
Comes to show: never give your audience a box of rocks if you live in a glass house.