What does Book Jerker mean?

Book Jerker meaning in Urban Dictionary

short for "Facebook-Jerker-Offer," denoting a seriously creepy guy with very few pals who makes use of his time for you to stalk those he understands, or does not know, and also to masturbate to photos of these making weird faces at a camera with which they tend to be using a picture of themself next to any and every other person into the room.