Hopefully most of the usage will be honorable. My personal approach would be to almost all of the time either Upvote something or leave it alone.
I can, however, imagine a small percentage of the time possibly using a Downvote simply to reflect that I think the suggestion made truly is a risky or bad idea, but would relegate it to hopefully quite rare usage.
Like if someone suggested automation that edited the boss's registry and changed his username or something. Ha ha. I might DV it.