I think if I'd notice that I always tend to downvote some person's comments when I see them, I might end up looking at their history for comments I'm likely to also disfavor. But I wouldn't downvote their comments just because they're the one who made them; I'd judge each comment individually. I don't know if this is against community norms.

I've done a minor version of mass downvoting-- I normally let mildly annoying comments go, but I'll downvote them if they're from one particular poster.

Two features of this poll make me doubt its usefulness:

1. You don't define 'systematic'. I've gone through user histories and looked at lots of their old comments, doling out lots of positive or negative karma in a short period of time based on the quality of the old comments. But I have no idea whether that makes me a 'systematic downvoter' or 'mass downvoter' in the sense people here are worried about. Your last question is particularly ambiguous, since it's not clear whether 'e.g. looking if a user has a history of other bad comments' is meant to be an example of 'systematic' or of 'not systematic' down-voting.

2. You don't allow people to express agnostic or highly uncertain views about anything. You allow 'tends toward X' and 'don't care', but not 'I don't know'. I think I gave overly extreme answers because I do care about this issue and about whether it's harming the community, but I don't have a clear view yet of whether it's net harmful.

I wasn't logged in when I initially filled out this survey, and the cookies in my browser might have been acting funny for whatever reason. So, I may have mistakenly filled out this form twice. If I did without anonymity, ignore my duplicate result. If it was anonymous, and it appears a user did enter twice, and the results are the same, then ignore one of them, as it could easily be from me.

I disagree about having this problem solved by moderators. Changing the karma system would be preferable i.e. by removing the downvotes or having downvotes only affect the individual post but not on the total karma of the user.