Dear Concerned,
I noticed at least three different major shake-ups in the ratings, the first one around 11 AM EDT Wednesday, when most of the essays at the top (including mine, which was #1 at the time) fell around 15 places and were replaced at the top by entries from as far down the list as 30 or lower.
Sergey Fedosin's message came after this, and I can't see any reason why someone intent on manipulating the vote would choose to draw attention to himself. When I first saw the message, before even seeing who had sent it, I interpreted "why your rating dropped" as some childish person gloating over down-voting my essay, but after reading it I realized that he was just trying to explain his displeasure with the voting procedure, and that the way in which the message was expressed was merely a reflection of the fact that English is not his first language.
As you pointed out, more grotesque changes in the rankings continued after this. I noticed yesterday that essays I knew I had already rated displayed the "do you want to rate this essay?" message at the top. A number of submissions went unrated by me at the end because I did not want to risk double-voting. I am sure others felt the same way, and this itself affected the process.
It would be too great a demand on human nature to expect those near the cutoff who were left out in the end not to feel cheated, particularly if they appeared above the cutoff when the clock ran out. In my opinion, there were many more than 35 deserving essays, including two or three in particular that did not make the final round, yet will likely prove to contain some of the most important ideas of any in the contest. Take care,
Ben