As previously noted in this blog, the practice of double-blind refereeing is often compromised by authors who cite their own previous work in their draft papers submitted for review.
It is in the author's interest to maintain their anonymity, and the main reason for doing this is to protect unknown authors from being dismissed out of hand. It is easy enough for an author to cite his or her own work as "Anonymous, Year" and to enter "Reference omitted for purposes of refereeing, to be inserted in the event of acceptance", or similar, in the list of references. If authors choose deliberately to reveal their identity, there are many other ways that they can do this, so we do not expend a lot of editorial time on trying to overcome this. It is rarely such an obvious method of revealing an author's identity that surely it cannot be accidental?