Hello,
I was just on ifixit when I noticed joyboi answered something. I just thought to myself, oh jeez. Look at my last post on ifixit meta. So I looked at his user profile and I just looked at it for a sec and then thought what the hack how is this possible? His rep should be -15 but it's 7. Here's a pic:
How is this possible? Is he a hacker?
Those numbers certainly look a little wonky! I'm looking into this now. I'll let you know what we find =)
So I think what happened was: Joyboi had a few of his Answers accepted, which gave him some Rep, but then those answers were deleted (by Joyboi himself, he has deleted many of his own posts for some reason). Deleting the Answers removed the record of the "added an Answer" and the "Answer was accepted" from his Activity page, but did not remove the reputation he earned. So even though he only has negative reputation currently listed, he did earn some unaccounted for reputation in the past. Hence the weird numbers.
That was a heck of a puzzle, I hope I explained that well? I'm having our developers look into the reputation system to be sure that's really what happened, and we may have to treat deleted posts differently in the future to show this kind of this more clearly!
Thanks for your sharp eyes!
8 
3 
1