As far as other closed threads there haven't been too many (a sign that we really don't close many from my perspective). We also haven't had that many times where we have had multiple discussions occurring at the same time on the same topic.
In addition, the In Our Opinion and Letters to the Editor postings are something new. This is the first time since we started posting those that we have had a column (which belongs in the In Our Opinion area) respond to a Letter to the Editor (which belongs in the Letters to the Editor area). It could have been even more confusing to follow if the original column that lead to the letter had been posted. That column would also be closed now because the Letter to the Editor would have been important to the discussion and would be where all new posts on the topic should have been.
Jeff, there has only been one person who has been permanently banned. We have closed topics before. We also have edited a few posts (language, attacks, etc.). We haven't closed topics just because we don't like them (even ones directly attacking our products).
The closed thread can be found at: 1st Thread
The followup can be found at: 2nd Thread
We are just trying to keep the discussions organized and make sure everyone has seen all of the discussion on the topic before they reply.