&gt; <i>My understanding of this phenomenon is that only people with extreme views comment.</i><p>Definitely not <i>only</i>, but you&#x27;ve put your finger on an important point here: such people are far more likely to comment, making the threads a distorted image of the community.<p>I feel like this is one of those phenomena that has a well-known name, but can&#x27;t think of it. Anybody know?