Bruno Wollman pointed me to an excellent article on the ignorance of expertise and confidence of the dumb. Here’s the TL&DR summary (but you should really read the whole thing):

• The expert isn’t always right;
• An expert is far more likely to be right than you are;
• Experts come in many flavors – usually you need a combination of education and expertise;
• In any discussion, you have a positive obligation to learn at least enough to make the conversation possible. University of Google doesn’t count;
• While you’re entitled to have an opinion, having a strong opinion isn’t the same as knowing something.

Enjoy ;)