This is a collective thread for users kkrryyzz, user GOODfellow, John Smithe, and Sha-bam! [Note: all accounts have been deleted.]. They were first brought to attention by Kalinin in chat after he checked his author page (screenshot here, and didn't request any particular action (if I recall correctly), but something to keep an eye on.
SCP-2609 was posted by kkrryyzz yesterday and had, within 50 minutes, gathered a number of upvotes by the other three users. (It had quickly dropped after being brought up in #site19 with .lc.) Their voting history can be seen here:
kkrryyzz (has changed their name from kkrryyzz242478, but the site will update within a day or two)
John Smithe
GOODfellow
Sha-Bam!
All of them have similar account creation/site join dates, similar voting history, and whatnot. I think kaktus has more and will comment, but this is the initial starting point.
EDIT: Sha-Bam! deleted their account after the thread went up.
EDIT: Now all but John Smithe have deleted.