I'm probably pissing off a few Facebook friends. They will "Share" old "memes" that have been circulating for ages, and have been proven false for almost as long. Whenever I see these, I post the link that proves the thing is false in the comments, usually a Snopes.com link. There were two more this morning in my feed.
Personally, I do a little research before I share just "anything". That is what search engines are for! ONLY if I can confirm something, do I repost it.