Why there's a lot of downvoting happening on steemit on the past few days even though posts didn't violated steemit's policy?
I got 1 downvote a few days ago and I reviewed my post if I violated any policy. Then I saw a post from another user telling that she also got downvotes and even her friends got downvotes even as far as they know they didn't violated any policy. I hope someone could answer this.
There are a number of accounts going around downvoting everything at the moment. I have received some flags myself. According to the article below all these accounts are the work of one person:

The good news is that:
* Their SP and voting power is too small to have any financial effect on your posts
* Their account reputations are lower than yours so their flags don't affect your reputation
* Steemcleaners are gradually cleaning them up by removing their delegated Steem (the Steem account provides the initial 15SP to all new external accounts but this delegation can be removed)
* You didn't do anything wrong, so there's nothing to worry about.

The easiest way to check if you are being flagged by one of these accounts is to look at Steemd. Here's your flagger:
* 15 SP
* Voting power: 20%
* Nothing but downvotes

It's not something to worry about.
The downvoting is a feature that is meant to help
Reduce spamming on steemit because the downvoting was created as a feature which someone can use to downvote any post which they feel is of low quality or it is like spamming post

But these days the issue is that some people now downvote for no good reasons,some just want
To downvote people just to make their own content trend more than the downvoted content
There are spammers now downvoting for no good reasons,they just downvote as a way to hurt others or just do it for fun

Downvoting even become more effective when the person downvoting have huge steempowers,i have also seen some whales on steemit that downvote each other especially contents on the trending page of steemit
Downvote occurs when from Upvote, our post can be downvoted if it is considered doing plagiarism and copy paste or trace, or disliked by others who have a large SP (steempower) and it is very influential.

Flagging occurs when content is offensive and offensive and rewards the rewards we receive, many flag rewards, with Steem Power owned by someone, by flagging, in an instant rewards to $ 0.00.
There has been a flag bot made by a few madmen. It's okay that they do not have voting power.
jealousy , people are downvoting others because they dont see other earning money and they are not. because if you didnt like the content , you can directly comment and said why you didnt like a post but downvoting someone's effort is definitely not the right option,