[Silhouette]

And indeed on reddit, the highest quality subreddit, /r/science, is the one most aggressively moderated

Although IMHO their extreme stance on moderation is not always a good thing. For example, they have an unwritten (at least, the last time I checked) policy of nuking entire threads where there are some poor comments, even if this also results in deleting many useful comments later in the same thread.

The first time I contributed substantially to a discussion in /r/science, on a subject where I did have something resembling an expert opinion to offer, my entire contribution (which took several hours to write across a handful of comments, with carefully backed sources etc.) was summarily deleted without warning. I queried this with the mods, and they explained the policy about nuking entire threads. Given the nature of some of the early comments around that thread, I couldn't disagree with the assessment that they were not a constructive contribution. However, I also immediately filed the whole sub in the same dustbin as SO and have made no further attempts to contribute, for much the same reasons.