I was looking at one of my old answers, and I noticed that all the comments below the answer had been deleted. I'm curious about why this has been done. The comments weren't argumentative; they were people asking for more information, and me giving it to them. I'm not saying that there was anything brilliant in the comments, but I don't understand why they were removed.
What is the criteria for deleting a comment (by someone else), and who has the power to decide that a comment should be deleted?