I have noticed a deterioration in the quality of comments in the last month or so. While mean spirited, intellectually bankrupt remarks used to be rare, they are now occurring more than occasionally. And the number of ad hominem attacks, both on other readers and post authors, has also increased.
Although I am not reading comments as often during the day as I used to, trust me, I do read all comments. Ad hominem attacks will be deleted. Snarkiness directed at the argument made in a comment is permitted if the writer has indeed put his foot in his mouth and might benefit from being told that, but slurs on its author are not (although I am sometimes tempted to let them stand, since they generally serve to reveal bigotry or ignorance).
One of the most valuable elements of this blog has been its high quality of comments. Nastiness is a disservice to the community and will not be tolerated.
I will also block IP addresses of serious offenders.