It wasn't unethical and in fact informing his subjects they were being observed would negatively impact the quality of the study (from what I understand). Informing someone that you will observe them cannot do anything except impact their behavior. Even if they choose to act as they already were, the fact that it becomes a conscious choice instead of an unchallenged course of action would alter what the study 'results' would 'say.'

In fact it's possibly a bit rash of backtoyoujim to assume he was even part of the experiment, other than by dint of the fact that he was using the same site as someone else who was doing a thing on that website.

I followed the top five of the most badged, active posters, popular commenters, and active commenters.

btyj is actually none of these, at this current time.

I don't think observational studies (this is far more accurately a study than an experiment) can actually harm or impact a person's experience or behavior. If they do, then they clearly fail at being observational studies. I am all for people trying to observe behavior and patterns through publicly available and publicly taken information/actions, especially in such a benign scenario as "what is the behavior and pattern en masse"? I don't see how these studies can hurt the groups they observe really, so long as the observation is nonobtrusive.

Now, watch-watch-watch, collect my data, and sell it? That of course is a problem and I'd be super pissed and so on. However...

...not what's happening here.

Carry on with the navel-gazing, less so of the outbursts that non-private information was collected by a co-user/co-inhabitant/co-person to look at for group behavior/information out of sheer curiosity and theory-testing.