facebook ghosting 

quickly logging off or appearing offline on Facebook to avoid a certain person.

john: i think Jane has been Facebook ghosting, she seems to log off every time i log on

facebook ghosting by bic boi dan July 25, 2011

Facebook Ghosting 

The act of reading through Facebook... but not actually commenting/posting/liking, thereby not leaving any trace of being there.

#1; Aric's never on Facebook anymore!
#2; Na man, he's always on! He just loves Facebook Ghosting.

Facebook Ghosting by jessiemh August 9, 2010