When someone will not stop posting facebook posts, no matter how many people dont care
"Jim has got a bad case of facebook diarrhea. He will not posting posts"
"I know. Does he actually think people care about him?"
The case where someone can't stop themselves from posting every insignificant thought or occurrence to their Facebook status. Similar to diarrhea of the mouth but for social networks.
Joe: Damn, Jill changes her Facebook status like every 5 minutes!
Mary: I know, That skank has Facebook diarrhea.