Should anyone be interested in this strange state of affairs -- I found that the DISQUS web site explains that when you 'delete' a comment what happens is that it is 'anonymised'. I contacted them to complain about this misleading situation and they explained to me that the reason you're not allowed to delete your own comments is that technically they are owned by the web site. Fancy that! That riposte is ridiculous given that you _are_ allowed to edit your own comments, so that if forewarned about the situation you can just replace the text by something like 'comment deleted by poster', and then press 'save edit'. Data correctness gone mad, it seems to me!