Not sure, really. My first reaction: ignore those shit and safe your votingpower for upvoting good content. Then I took a look at this accounts and I said instantly „what the heck!? Nuke them!“
But the huge problem behind this is not so much the abuse of voting-bots to get „rich in short time“. It is the mentality of seeing an opportunity to infiltrate a system where others work hard to deliver value. Yesterday I read the whitepaper of steemit and as far as I understood, those spammers are not welcomed, but accepted up to a certain point because -even if it’s garbage – they are still taking action.

So I perceive steemit as a living entity that has an „immune system“ against such viruses. You can ignore, flag, blacklist etc. to let them starve out. So we could only wait and hope, they will lose interest in this. BUT you have to consider, that even 0,2 SBD for people in developing countries is much money. So they will find it still worthy to open even more accounts to spread useless content to gain even a few cents. And this can become epidemic, where the normal „immune system“ of steemit might need some support. I am really concerned at the moment and have no idea how to prevent this. At least I think it’s not helpful to „nuke them“, because it’s easy to open a new account and start with fresh reputation lvl 25.

It’s a matter of education I think. There are so many good guides and advices here on steemit, how to make it right. But when they are ignored by spammers, you can shout as loud as you can - they won’t hear you. Spammers gonna spam... :(