Defensive reaction to finding out someone is not on Facebook. Usually indicated by the word "just". As in, "I just use it to stay in touch with friends/family".
If I happen to mention that I'm not on Facebook, nine times out of ten someone's Facebook Guilt kicks in, even though I have made no judgement whatsoever.
"Facebook know" means to know someone only through Facebook. You've never met, talked or texted, but you know many details about each other through posts that appear in the other person's feed and replies to those posts.
When someone posts an inspirational status on Facebook that is very open ended and mysterious in hopes of getting people to comment on their post. Facebook inspiration fishing is most often used to get people ask them what they are up too. Commonly used when they really want to tell their friends about this cool new Herbal Tea, Knife set, and/or mixtape and unsure how to do it.
Facebook status: "On the hunt about to make everyone take notice and change the world."
Comment: What you doing cuz? Do I want in?
Response by poster: Yea bro, I'll inbox you?
Inbox
Facebook poster in the inbox: Yo man I'm about to drop my new mixtape tonight, do you mind sharing the link?
commenter: Man...you just Facebook inspiration fishing
When someonegoes on a rant about how everyone is fake and phony or how they always need a break too. Then threatens to leave Facebook ( or social media ) forever on one of their Facebook statuses to get attention.
"Omg. I swear Breesha stay havin' a Facebook funeral. I wish she would just log off!!"