short for "Facebook-Jerker-Offer," denoting a seriously creepy dude with very few friends who uses his time to stalk those he knows, or doesn't know, and to masturbate to pictures of them making weird faces at a camera with which they are taking a picture of themself next to any and every other person in the room.
Mark Warner is a total book jerker.
"Yo, dude, who is that chick?"
"I dunno. She's hot."
"You're a total book jerker." (Leaves)