Everything you see on the Internet -- even my own blogs -- should be viewed with a degree of skepticism, a healthy skill that you must cultivate. The farther the source is from a professionally published website, the more skepticism you must apply. I see people who fall victim to Facebooks scams like free airline tickets. More often that not, the widespread Facebook posts about changing your security settings are largely misinformation. People want to believe this stuff, and they want to believe their family and friends too.
The plain truth is, wishful thinking does not protect against misinformation. Worse, misinformation often is cover for an Internet-based attack on you. We don't know who really did say "There's a sucker born every minute", but the point is well-taken.
Here is my plea: learn how to use, and then use religiously, the most important website on the Internet. It is called Snopes. Subscribe to their free weekly newsletter. Before you re-post anything in Facebook or email that might be wrong, check the Snopes library of urban legends and misinformation. Snopes has over 250 entries for Facebook alone.
Other useful websites are the Statistical Assessment Service and Truth or Fiction. Take responsibility for not spreading misinformation. And when someone else does, gently correct them. Life is difficult enough without being steered in the wrong direction.