sneaking or stalking someone/thing;especially if you are a Zerg

A lurker is someone that follows the forum but doesn’t post.

n. The guy who hangs out by the dumpster in the 7-11 parking lot. He doesn't really ever do anything; he just looks like he's about to. The Lurker has a well groomed molestache and still listens to Snow and Vanilla Ice. Also seen at NASCAR events.

People who look at your myspace and dont leave comments, messages, pic comments, etc.

someone who seems to always be present bu unnoticed

Someone who "lurks" around an Internet forum, only reading and never posting. "Lurking" is often the result of being too scared or lazy to register, and the term mostly applies to those who do not; however you do get the occasional member who doesn't post.

one who reads a blog without ever commenting on the posts