Yes, @valoom is one example of these accounts.
We downvoted your upvotes.

I suggest that you just downvote detected plagiarists in my community and let me know about it (like in this new case) so that I can mute them accordingly (for me myself it is partly very difficult to judge if someone plagiarizes or simply is making great photos).

You don't verify these "new" accounts to find out if these are actual new users. Actually real people. Just because the account is new, it does not mean that there is a real person behind it.
The modus operandi of this scammer is quite obvious and predictable. He has been attempting to scam your votes for a while. These fake accounts are easy to spot.
We cannot take responsibility for each community to do due diligence for them. There are dozens of communities.
Just this one scammer alone spams tags in multiple of them.
Each reward that he earns from automated curation allows him and incentivises him to create more accounts to continue scamming.