That's what it seems like to me as well. From what I can tell, they are bots that are being set to target members of certain curation clubs, voting exchanges, tribes, pools, etc.

I have only been downvoted once since returning to Steemit, ironically on my first post back. Eventually, I am sure it will happen more but will ignore it.

My recommendation is that the @Steemit development team make it a requirement to manually enter comments for any downvote. I could even support this for upvotes as well.

I agree with Jon and Blain, screw em! .......... I'm here for the party!