I'm not sure about everyone else, but the bots and accounts that only downvote for no reason whatsoever should be able to be downvoted by the community to a point where they can no longer vote.
It is quite a useless ability if bots ruin legitimate posts and cause them to be hidden...
Here are some bots I know of, comment on any you know of:
Cheetah - claims the need to downvote because your content may be similar to someone else. How is this legit? If I want to post similar content because it's my idea there is no legit reason to downvote because someone else posted what the bot thinks was similar
blacklist-a Just a generic blacklister and downvoter, no logic or reasoning
adm Appears to simply be a secondary account so someone can just downvote for no logical reason.
Hope this helps.
Who am I?
BORIS!