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

lil mad is like big mad but the opposite, you mad but not mad to the extent of pullin somthin

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

A person who is just "there." Nobody really knows why, other than they show up and don't say a word. Possible reasons for this could be:
-They don't know what to say
-They are pretending to have friends
-They are trying to scare you
-They are there just to be seen with you, as if they have some kind of relationship with you.