A physical version of "Are you kidding me?" is the eye roll. It's not something I do externally but I have done it internally when talking to people about farming and the food we eat. I do it more than I like and it's gotten to the point that I'm ecstatic if the people I'm talking to have some right information!
Before there was internet, TV, radio or newspapers we had each other for information. In villages and towns news traveled from person to person. Depending on who the source of the info was, we could determine how truthful that information was. New information was always big news and I'm sure many storytellers were very good at spicing up the stories to get more attention. Times haven't changed that much.
Now the internet is a great source of information and news. It is a vast and unending sea of "information villages" ready to supply you with any answer to a question you type into Google. The problem is, we don't know who the villagers are and who is supplying the answers.
When I ask someone where the heard misinformation, nine times out of ten they've read it on the internet or someone they know told them. We still trust our neighbors and friends more than we trust someone we don't know.
So how do we correct misinformation? Talk to experts and I don't mean self proclaimed experts but those who have a long standing reputation in what they're doing. The farmers I get my information from are multi-generational and the sources I read from are accredited State University studies.
Talk to the sources of the info. Anyone can hide behind a computer and state anything! Get out and actually meet the source and find out if they know what they're talking about.
The most important thing to remember is; don't believe everything you read on the internet or hear from your neighbor, check it out for yourself!