18th Nov: We've switched servers and will be updating the old code over the next couple months, meaning that several things might break. Please report issues here.
A Lurker is the internet equivalent of that creepy guy at the party who stands in the corner all night, listening to other people's conversations, and no one can remember who invited him. Except somewhat less creepy (as you don't see him). Some lurkers will sign up for a forum but rarely post anything even though they read most of what does get posted. Other lurkers, on publicly viewable forums, won't even sign up. Sometimes lurking is a prelude to becoming a regular poster on the forum. Either the lurker likes what they see and decides to become an active part of the community, or they were intending to join all along and merely lurked to get a handle on the unspoken rules and zeitgeist of the forum. Thus, a period of lurking can help one bypass the noob stage of the forum poster life cycle. Lurking for this purpose is strongly encouraged as a survival mechanism on certain meme-heavy corners of the Internet, hence the phrase "Lurk moar". However, if one admits to formerly being a lurker, the registered users might be creeped out that the information they posted on a publicly viewable forum is being viewed by the public. Related to the Unknown Troper. Not related to the advanced/evolved form of a Zerg Hydralisk, nor the homeless people on Babylon 5. Some sites, such as 4chan, will actually suggest that you should "lurk moar" if you prove ignorant of the etiquette, such as it is. Sometimes the reason for only lurking on a TV-show's forum is that by the time the show airs in the lurker's country, everything useful has already been said.