The traditional meaning of ' to lurk ' ( and thus the term ' lurker ') is a pejorative term( implying contempt or distrust ):
Definition of lurk. intransitive verb. 1a : to lie in wait in a place of concealment especially for an evil purpose someone out there lurking in the shadows.
BUT I note too that apparently now the term ' lurker ' in a social media / internet context has the meaning you suggest ie someone watching but not participating.
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Anyway, there are many who watch and read here without posting anything themselves for a variety of perfectly good reasons.
