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.
@6AND5: that still doesn't indicate the purpose of knowing that they are related parties. An interest in a relationship alone is not a reason for checkuser. There would be need for a proof of wrongdoing, circumventing votes, circumventing blocks, etc. — billinghurstsDrewth 07:03, 24 January 2015 (UTC)
The question is that the participant (Lakiditto098 (same 1221nor, Lilit1345, Karenpetrosyan)The following accounts are Confirmed) is blocked (unlimited), and now his brother allegedly began to write articles. --6AND5 (talk) 14:11, 24 January 2015 (UTC)
If it is his brother that may or may not mean the same IP address. It may or may not mean the same user agents, etc. There is nothing that we can do that is going to differentiate that sort of relationship and you will need to work it out for yourself. — billinghurstsDrewth 11:24, 25 January 2015 (UTC)
Member admitted he and his brother one person.--6AND5 (talk) 14:04, 25 January 2015 (UTC)
Thanks for getting back to us. Closed Issue resolved by community. — billinghurstsDrewth 14:05, 25 January 2015 (UTC)
User:Ruslik0, а можно показывать все новые записи этого участника в армянской Википедии ?--6AND5 (talk) 14:16, 24 February 2015 (UTC)
Reason(s): There seems to be a close relation between, at least, the accounts of Gtrbolivar, Bakalisb and Skettos7, as they have the same type of contributions, with their interest being centered in articles like Πανελλήνιος Γ.Σ., Αθλητική Ένωση Κωνσταντινουπόλεως, Ολυμπιακός Σύνδεσμος Φιλάθλων Πειραιώς or Παναθηναϊκός Αθλητικός Όμιλος. But where the problem is, it's at the fact that those three accounts have the same type of argumentation and the same kind of acting, which means reverting (blindly in my opinion) every contribution which is not ok with their personnal beliefs and can have the same rather aggressive talk when someone tells them publically that he disagrees with them. Also, what is making me think that we have here a sock-puppeting case is the fact that all those accounts don't appear all at once but for separate periods ex. for two months (I might be wrong about the length of that time period...) you have only Bakalisb contributing, and then he disappears and you have, for example, Gtrbolivar appearing from nowhere when he was inactive for around two-three months (again I might be wrong about the time length)... Well, let's say that all of this makes the whole situation rather suspicious. And as for Picker78, I think he's the puppet creator as in the past he was, already, suspected for creating puppets and he had the same type of contributions and argumentation with the mentioned before users... Thanks in advance...
PS. Sorry for any english mistakes... Glorious 93 (talk) 23:09, 19 February 2015 (UTC)
In my opinion, Bakalisb is a serious contributor and he/she is not involved in this on going sock-puppeting case. On the other hand, Gavros (active from April to July 2014) seems to had shared identical interests, argumentation and bad temper with Skettos7 (account creation in December 2014). --Στέλιος Πετρουλάκης (talk) 00:40, 21 February 2015 (UTC)
Has this matter been discussed at elWP? The request should be discussed at that wiki prior to progressing here. — billinghurstsDrewth 08:51, 21 February 2015 (UTC)
Every time we (as users) want to discuss such matters (sock puppetry cases) with admins at el@wiki, they tell us first to ask for a checkuser so we can prove that our suspicions are right and, then, start a discussion about taking measures against those users if the checkuser is positive. So, I don't think that sending back the problem to el@wiki (and then being told, again, to send it to meta) would help in this case and in sock puppetry cases in general. Some of these two bodies (el@wiki admins and meta stewards) has to take a decision and sending (indirectly of course) the problem to each other won't help in that direction. Just an example to prove you what I'm saying here, in a quite similar case, with an obvious puppet, an admin responded me by saying "Κανείς διαχειριστής ή γραφειοκράτης δεν έχει δυνατότητα διαπίστωσης μαριονέτας (ή μη) στην ελληνόφωνη ΒΠ. Αν έχεις σχετικές υπόνοιες μπορείς να ζητήσεις Checkuser στο meta."-"No admin or bureaucrat is able to prove if a user is a puppet or not on el@wiki. If you have any suspicions you can ask for a Checkuser on meta." And there are numerous cases like this with this same (or nearly) answer from admins. Letting down the matter wouldn't help at all.--Glorious 93 (talk) 12:38, 21 February 2015 (UTC)
Having multiple accounts is not contrary to WMF policy, so that itself is not a consideration for stewards. For a local policy for stewards to run a checkuser the checkuser policy directs us that a conversation should take place on the local wiki, so where a general user has a case it should be supported on the local wiki by those who are charged with enforcing the policy. In this case I believe that we need a local discussion at elWP. — billinghurstsDrewth 12:53, 21 February 2015 (UTC)
Closed stale discussion, no comment for a week. — billinghurstsDrewth 13:09, 28 February 2015 (UTC)
Reason(s): These are multiple accounts with only one vandalism edit. Please track and block them globally. Maybe there are more usernames, please check. Петър Петров (talk) 17:06, 22 February 2015 (UTC)
I locked Ridler o arnold. All other accounts are already locked. Ruslik (talk) 19:21, 22 February 2015 (UTC)
Reason(s): Extensive sockpuppetry, main account indefinitely blocked on both nowp and enwp (no:Bruker:Sju hav/w:User:Sju hav) in 2008. Has been very active lately, and all accounts listed above exept for the first have been blocked based on behaviour and topics of interest (Ogaysiis was also blocked on enwp after a local CU). Idoll-olga was created today, and although the contributions so far have been "innocent", the behaviour is quite recognisable: Starting by asking questions on talk pages, adding text (often trivial) citing newspaper articles, some "finger prints" in the edit pattern that I would prefer not to disclose openly. 4ing (talk) 21:20, 23 February 2015 (UTC)
All those accounts are confirmed sockpuppets from one of two IPs (one mobile the other fixed). Scargsmint, Elis20005 and Video Frankenstein are three socks not included in that list, though the last is already blocked. I'm not sure if they are good candidates for a global lock given that some accounts appear to be editing productively; if another stewards wants to look into it further they are free too. I need to go and write a test now. Ajraddatz (talk) 18:22, 24 February 2015 (UTC)
Thank you, I have blocked two of the accounts not already blocked. - 4ing (talk) 09:42, 25 February 2015 (UTC)
Not done please present consensus at faWP for this request. — billinghurstsDrewth 14:21, 28 February 2015 (UTC)
@Billinghurst: As much as I don't agree with behavior of this reporter, I don't agree with behavior users who this user reported, all of them are violent with NPOV, it's truly says that this user is actively edits against Iranian government which is against NPOV, I also checked some of edits by users who are reported, adding content to support Iranian government and telling will add the references or adding non-trusted resources, it seems some of them might match and already blocked in fawiki. some of fawiki admins can't take action against users being supportive with Iranian government because they live in Iran. if there is policy called "suckpopet" it must act same for all, not only for some specific users. could you please tell me where is the consensus for other two requests? Mjbmr (discussion • contribs) 15:54, 28 February 2015 (UTC)
This request was disputed. This was also a longer list of names and contained names of users previously checked. As it is a seemingly coverall rquest, rather than a specific case it is closer to fishing, which is not the basis for checkuser and without a better evidence-base it should not be undertaken. Administrators at faWP are aware of alternate means to have checkuser requests undertaken if required. Further, I doubt that we should be taking requests from sockpuppets who will not be able to implement any result from a checkuser. — billinghurstsDrewth 16:17, 28 February 2015 (UTC)
To note that stewards undertaking checkusers is neither for nor against pro-/anti-government editing, it is for sock puppetry as per the policy. The community will decide about specific editing on the wiki, that is not the role of stewards. — billinghurstsDrewth 16:24, 28 February 2015 (UTC)
I agree with you we should not accept request from sockpuppets, but you said consensus. My latest CU request was also not done while I was the admin that wiki. according to  User:Dostatdaram was already matched and blocked. User:Badieem also has a very violent edits with NPOV, reed this, even a machine translated would say what this is about, it truly says there is no freedom for news reporters in the U.S. relying on an Iranian internal source, the content is still there, wikipedia is not what it suppose to be. Mjbmr (discussion • contribs) 16:26, 28 February 2015 (UTC)
Confirmed Dmitryne, KuznecovGrigory, Ruþín16, OstapBinder, MedvedevDmitriy. He did a pretty good attempt to cover tracks. Almost had me missing it. I don't speak Russian, though I do speak CU and IP. <g> — billinghurstsDrewth 14:46, 28 February 2015 (UTC)