Hardfork 19 just took place, and they have reworked the influence power settings. It will now be better to get wide spread notice (many up votes) from low influence (new) users, than just one or two high influence users. In the past a single 'whale' up-voting could add several dollars to your post, or worse a 'whale' down vote could erase the value of 100's of up votes.
As well, the power of a users influence degrades after a few up-votes, so if the people that voted up your posts were spamming their up-votes that day, they now count for less than previously.
What's a whale in steemit and how can this downvote occur?
A lot of people talked about downvotes but I can't find a button.
A 'whale' is an account the contains lots of steem power, thus influencing the payout of a post greatly. There are many accounts on Steemit with over 1million Steem Power, and a fully powered up vote can add 100's of dollars in payout, the down vote of a post can also erase 100's of dollars in potential payout. I have never down voted a post to this point, but it is done by using the flag icon. Down voting was meant to draw attention to post that plagiarizes another persons work, or doesn't follow the spirit of Steemit in some manner. To just cut and paste an article found on the web, and post it as your own material is dishonest, to earn money for doing so only make it worse, so down voting accounts that do that, is our way of lowering their rep and removing the payout. There are some accounts that down vote just out of spite however. Myself, I just move on and don't subscribe to people who do that.
Okay. Now I understand.