David, it was intended in jest, and, if you have a look in Miscellany, you will see that the "damage" done is very temporary. Already most of the old threads that I revived are slipping down the page, and will no doubt be gone completely before too long. The same will happen to all the other traces of my prank, and, since at least one or two of the old threads have generated new responses, I don't consider it to have been a total waste of time.