1. A person who interupts a conversation , either real life chat or on a computer and takes over the conversation thus killing the former convo thread and turning the attention of those interupted to the interupter.
2. Any one who takes a funny picture , thread joke ect from some one and posts it claiming it for there own before the original owner can post it.
Guy 1 " Hey man I was watching Tv last night and cought this show , the walking dead have you ever seen it?"
Guy 2 "No but i heard it S---"
Chat Jacker "Omg I saw a TV show on whales last night !! whales are epic blah blah blah!!!"
Guy 1 and 2 "Bro we been chat jacked