Lurking
From sciforums_encyclopedia
Lurking, adj. (from verb: to lurk). To view a discussion/forum without making a contribution. Many people start out lurking, before eventually making their first post. It's recommended behaviour for beginners as it gives you a chance to learn the lack of etiquette of the forum, and stops you from stumbling in waist-deep and making a total arse of yourself. Naturally this doesn't apply to those lurkers who are stalkers, flamers or trolls, and who lurk in order to be able to handpick a victim.
Lurking in real life (creeping around in the dark) is quite good fun.