Make sure you have a good reason for the check. It will only be accepted to counter vandalism or disruption to Wikimedia wikis. Valid reasons include needing a block of the underlying IP or IP range, disruptive sockpuppetry, vote-stacking, and similar disruption where the technical evidence from running a check would prevent or reduce further disruption.
Be specific in your reasons. Ambiguous or insufficient reasons will cause delays. Explain the disruption and why you believe the accounts are related, ideally using diff links or other evidence.
Make sure there are no local checkusers or policies.
It looks like a duck to me, but if check is still required please say so. Also, without much time currently any other steward should feel free to take this one. —MarcoAurelio 11:55, 22 April 2017 (UTC)
Whether these are one person or a coordinated group from their own website probably does not matter at this point. Although a fourth name related to the site has appeared (SullivanBenjamin), there does not seem to be any continuing or spreading disruption beyond the one VFD. This can be closed until such time as further problems may develop. ~ Ningauble (talk) 12:38, 2 May 2017 (UTC)
Not done then, per above. Matiia (talk) 00:09, 3 May 2017 (UTC)
Reason(s): Behavior pattern suggests that Mihai 255 is a recent clone of Mihai7, blocked indefinitely for sockpuppetry. We are dealing here with a huge clone farm, only part of which was confirmed. You may uncover more. -- Victor Blacus (talk) 08:34, 30 April 2017 (UTC)
Confirmed. The full list is Mihai 2551, Mihai 255, Mihai 1, Mihai257, Mihai7, Mihai 25, Robert Ia and Robert l&. Ruslik (talk) 17:48, 30 April 2017 (UTC)
Reason(s): Al Balint (who may have a number of known clones that I cannot find right now) is the author of the autobiographical articles ro:Șerban Nichifor, da:Serban Nichifor and en:Șerban Nichifor. He recently created ro:Livia Nichifor and en:Livia Nichifor, the subject being his mother; the article on ro.wikipedia was proposed for deletion, the reason being lack of notability. He reacted with personal attacks (each of them replicated on two other pages) on two users ((1) and (2)) who had proposed or suported the deletion. A complaint was registered against him because of that behavior. He was warned, and after repeating the attack he was blocked. Now comes the actual CU request: the next five users mentioned (all of them but one registered after the discussion had begun) have expressed themselves against the deletion, citing the same unreliable sources as Al Balint. There is strong suspicion that they are sockpuppets, or meatpuppets, of Al Balint. -- Victor Blacus (talk) 13:56, 20 May 2017 (UTC)
The background info is somewhat superficial/imprecise. The actual request is about the listed users. Late edit. -- Victor Blacus (talk) 18:07, 22 May 2017 (UTC)
It looks like a prolific farm. Here's a fresh one:
Al Balint, Dr Damian and Marianamar are Confirmed to be the same user. Antal2017 is also Possible. The second group are Hiram of Tyre, Jeannedelciu and Phorion. Mirceacristescu may be related to DavidC. Verovero13 may also be related though I am not sure. Ruslik (talk) 03:30, 23 May 2017 (UTC)
@Ruslik: appeal - the result is totally wrong! Please check users with IP addresses. My IP address is: 22.214.171.124. Thank you!--Al Balint (talk) 10:10, 23 May 2017 (UTC)