I don't know, but mass upvoting is less likely to be complained about.
I wouldn't complain about a mysterious leap in my karma, but I'd find it unusual enough to wonder what was happening -- as when the scoring rules were changed to make votes on top-level posts in Main count for 10 points instead of 1.
Below is a message I just got from jackk. Some specifics have been redacted 1) so that we can discuss general policy rather than the details of this specific case 2) because presumption of innocence, just in case there happens to be an innocuous explanation to this.
So... thoughts? I have mod powers, but when I was granted them I was basically just told to use them to fight spam; there was never any discussion of any other policy, and I don't feel like I have the authority to decide on the suitable course of action without consulting the rest of the community.