I logged into SO this morning and found that I'd somehow lost 1,000 of my reputation points overnight. There's no indication of what happened or why. How can I get an explanation? Thanks.
It looks like the automated jobs saw a distinct pattern of voting - perhaps some well-meaning user voting excessively for your account. Those votes were cancelled. I stress that this is automated, not a personal thing - more details here and here - and those aren't meant in an accusatory tone - I'm just explaining why that process exists.
I'll take a quick look to see if there is an obvious reason...