Considering the policy of theocratic warfare and the Bible examples of spying on your enemies, I find it easy to believe that the WTS monitors this board and others. You need to consider what the benefits of the time and effort required to do this would be. Finding active elders, Bethelities, or other "important" JW's was already mentioned. The benefits of them weeding out "wolves in sheep's clothing" is pretty obvious. What probably scares them more is the potential threat of an organized apostate movement against them.
It's no secret that trying to collectively organize apostates to fight against the Borg is similar to trying to herd wild house cats together for some purpose. People who leave the WTS are often anxious to put as much distance as they can with the WTS, not to stay around and do battle with it. However, all this could change someday, as the collective anger we share against the Borg is a force to be feared by them. All it would take, IMHO is some really outrageous action against ex-JW's that everyone could relate to. I don't think the WTS ever wants to see that happen, not so much that we are superhumans but they know better than to stir up a hornet's nest.
Also, by knowing their enemies by reading this board and others, they can plan their damage control strategies. They are sure to get tip off's from what they read here that will slap them in the face in the near future. Look at the UN library card scandal for example.
I don't think they are really that interested in individuals and their "hedonistic" lives (at least that is how the WTS sees us) but if they ever found someone in the online world who had an amazing ability to organize people and rally them for a cause, you can bet the would be making a file on them.
Finally, I think they need apostates. Look at the example of America after the evil Soviet Union bit the dust and collapsed. There was a tremendous war machine looking for an enemy to fight. Our government had to invent one to keep the status quo. The Society needs an enemy, but apostates are only a pain in the ass now, not anything dangerous. If we were dangerous, they could use that to whip up more hate and motivate dubs to action. As it is now, there is more motive for dubs to visit McDonald's on a Saturday morning than go door to door. If they get desperate enough, they will make us all out to be the reincarnation of evil. I can hardly wait.
Skipper