I already flagged some who just spammed for followers.
But flagging because of self-voting...
As I said in another place: Self-voting is okay if you would have voted if someone else had written it.
But it is not only comments. Look at
He just embeds a youtube videoand upvotes himself for 20$.
https://steemit.com/@sandrino
That is surely misuse, but who can afford to downvote for 20$?
Yeah this is a relatively new issue, well it has always been there but due to the HF19 and most people's votes actually being worth something now it is far more visible.
I am only thinking about this and I don't quite have any good solutions that I can't also think of ways to circumvent.