Even though I have discord, I personally don't engage heavily myself. It is quite handy for announcements like these though!

I'm sure it is being looked into more deeply by the right people, but apparently there are quite a few accounts involved. Here is the official response/ message left in the discord servers of steemcleaners with regards to the flagging.

pjau [witness] - Yesterday at 05:06
Hello everyone, there are a number of accounts impersonating Steemcleaners and its members which have been downvoting users. The only accounts we have that we downvote users with are steemcleaners, spaminator, guard, mack-bot, cheetah and occasionally our personal accounts. We pretty much always leave a comment with the reason. Any other accounts are not us.

Below is a post, with regards to the flagging that was posted by the account guiltyparties yesterday.

https://steemit.com/flag/@guiltyparties/the-flag-ring

If you are subject to any constant flag abuse you can report the accounts at the website below, which is the official steemcleaners reporting website...best of all you can do it anonymously!

http://steemcleaners.com/reports/new

Hope this helps!