Facebook Humanitarian 

someone that joins and/or becomes fan of all types of "causes" on Facebook and is always posting on his/her wall something about helping the poor and suffering. However in real life this person does not live up to this at all.

Guy: "hey did you see Kendra's FB page, she's joined like a 100 causes and is always reminding us to don't forget about the suffering and to stay green.

Guy2 : She's sucha Facebook Humanitarian; last night my father saw her running away in her hummer after dumping her old tv down the street.

Facebook Humanitarian by Kakashi-Senpai March 5, 2010