Back...

I just found one post with somebody who search for spammer bots accounts and try to slow them down.

Maybe he can be helpful in some way.
I'll put below his post regarding that issue:

So I just flagged a spammer with ~3400 accounts voting numbered comments.. — Steemit
https://steemit.com/spam/@ausbitbank/so-i-just-flagged-a-spammer-with-3400-accounts-voting-numbered-comments

I haven't found yet the one with targeting unoriginal content.

Hope it helps a bit.