When friends post things to friend's walls and then delete them hoping to catch it before pissing them off, not realizing that most people with smart phones got the message before it even hit facebook.
facepost regret post something to your wall like : "Get off your soapbox!!" (meaning, I didn't vote the same as you in the last election)
A post in a forum that is meant to look serious, but is actually satirical or ironic. Many people often cannot discern fakeposts from 'real' posts and thus they miss the joke. For the lack of a better analogy, pretty much everythingStephen Colbert says on the Colbert Report is the IRL equivalent of a fakepost.
Someone that constantly posts radom shit on Facebook and annoys you. A preson whom you would like to delete from your friends list but feel you cant due to the fact that you like this person to much to offend them.