Today$^{[2]}$ I came across some MSE user profile and noticed that (s)he lost almost $10$k reputation on single day the reason being Serial up-voting reversed
AFAIK This faq post on meta says
Every night around $03:00$ UTC, a voting fraud detection script is run that looks for patterns
And it is very well known that a user can earn at most $200$ reputation (only from up-votes) and then it's obvious$^{[1]}$ that one cannot earn ~$10000$ reputation on one single day and I think that no matter what kind of fraud occurs, it's effect(reputation change) will be reversed within $24$ hours. Then it is impossible that one can could lose ~$10000$ rep due to reversal of serial up-voting.
Now that I have eliminated the impossible, whatever remains, however improbable, must be the truth
Then, Is this some kind of undocumented-feature? Could someone here explain this (with some reference)?
Thanks!
$[1]$ I have no citations for this $[2]$ Please excuse my English