I wish that all you people that consider lurking a dirty word  would come up to date. I am sure that there are people  "lurking " for sinister purposes  on this and other forums etc. But in this day and age for every one of the sinister ones there are  undoubtedly hundreds or thousands that "lurk" such as I do to gain some information, knowledge. I am 81 yrs old and I remember back about 35 years or so when my 2 daughters called me a "dirty old man" when they knew darned well that I took my seasonal bath every 3 months. :)). So now I suppose I am a "dirty old lurker" .  When I go surfing the Net, I pick a spot from my favorites list that I wish to go to.  My favorite list is about 6 pages long probably 200-300 places to go and "lurk"
Sure the Dictionaries carry an old definition of lurking - I'm betting that a new edition of every dictionary will carry an added definition covering the new usage
Bob Anibal