What is the feature that makes it so deadly? I suggest that it is the random reinforcement schedule: Every five minutes you "press the lever", that is, check forum X or site Y. And every six or seven checks you get the reward: Someone posted something interesting!

What I want to know is whether a random reinforcement schedule becomes more addictive when we add the possibility that pressing the lever will lead to something aversive (e.g., a particularly stupid comment or one in which someone expresses enthusiasm for a course of action I think will cause more harm that good). I kind of suspect that such a schedule is better at hooking me than a random reinforcement schedule without the possibility of aversive outcome.

ADDED. For example, I note that reading internet forums open to all comers like LW causes aversive reactions in me much more frequently than does reading professionally authored and edited publications, e.g., The Atlantic or Smithsonian magazine, and I note that I get more hooked on the former than on the latter.