Yes. Comments with −1 or lower karma are remarkable and generally glided over as provisionally bad unless the reader takes care not to, comments with 1-3 karma are not notable.
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.
As far as harming the goals of the community, is mass downvoting of a single user any different from mass upvoting of a single user?
Yes. Comments with −1 or lower karma are remarkable and generally glided over as provisionally bad unless the reader takes care not to, comments with 1-3 karma are not notable.
Has mass upvoting of a single user (by a single user—that is what we are talking about here) ever happened?
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.