OMG: used to express surprise, excitement, disbelief, etc.;
LOL: laughing out loud;
used chiefly in electronic communication to draw attention to a joke or amusing statement, or to express amusement;
noob: a person who is inexperienced in a particular sphere or activity, especially computing or the use of the Internet;
hashtag: a word or phrase preceded by a hash sign (#), used on social media sites such as Twitter to identify messages on a specific topic;
unfriend: remove (someone) from a list of friends or contacts on a social networking website;
troll: make a deliberately offensive or provocative online posting with the aim of upsetting someone or eliciting an angry response from them;