I have FB friends who post weird and incorrect stuff as well. One person I'm related to. On occasion I have responded with a link to Snopes or another authority if I think it's really dangerous advice. I can't say my "helpful" response has been seen as such much of the time, especially when they've started their post with something along the lines of: "Oh, this is very important news!!! Please make sure you do this because I love all of you and this is urgent for you to do right now!!!" Maybe they feel like they've been made a fool of in front of all their many conspiracy theory loving very dear, dear friends. I've blocked posts from some people just so I don't have to keep seeing stuff that makes me crazy. Not unfriended, I just don't need to see all the stuff they repost URGENTLY!!! My elderly Mother gets tons of forwarded emails from friends and relatives as well- no Facebook for them. She's stopped reading their emails completely and will probably never know when her friends have died unless she notices they stop forwarding junk emails.