I would imagine that all of us on some level are guilty of stalking. Call them “followers” on twitter, call it “friends” on facebook when in actuality you are nothing more than acquaintances. How many of you have been stalked however in a manner which made you want to take out a restraining order :)?
What are the lines for you beyond which it is not acceptable? Even for friends?
healthy curiosity and concern is nice and permisible. but stalkers, in the real sense of the term, have some problems in their mind so obviously this doesnt include in the healthy version of concern.