This page provides information about CheckUser access and outlines the policy on its use. It was discussed in September and October 2005, and went live in November 2005.

CheckUser status

CheckUser is an interface for users with the checkuser permission. A user with the checkuser permission on a wiki can, in particular, check if a user is a sockpuppet of another user on that wiki (not on all wikis). By using it, users are able to:

  • Determine from which IP addresses an account has performed edits, logged actions, or password resets on the Wikimedia wiki;
  • Determine all edits, logged actions, login attempts, and password resets that were performed on the Wikimedia wiki from a specific IP address (including users who were logged in with an account);
  • Determine whether the account being checked has sent an email using the MediaWiki interface to any other user. The time of the event is logged; the destination email address and destination account is obscured.

This information is only stored for a short period (currently 90 days), so edits made prior to that will not be shown via the CheckUser tool. A log is kept of who has made queries using the tool. This log is available to those with the checkuser-log permission:

See Help:CheckUser for the user manual.

Use of the tool

The tool is to be used to fight vandalism, spamming, to check for sockpuppet abuse, and to limit disruption of the project. It must be used only to prevent damage to any of the Wikimedia projects.

The tool should not be used for political control, to apply pressure on editors, or as a threat against another editor in a content dispute. There must be a valid reason to use the CheckUser tools to investigate a user. Note that alternative accounts are not forbidden, so long as they are not used in violation of the policies (examples of violations include double-voting, increasing the apparent support for any given position, or to evade blocks or bans).

Notification to the account that is checked is permitted but is not mandatory. Similarly, notification of the check to the community is not mandatory, but may be done subject to the provisions of the privacy policy.

Some wikis allow an editor's IPs to be checked upon their request if, for example, there is a need to provide evidence of innocence against a sockpuppet allegation; note, however, that requesting a CheckUser in these circumstances is sometimes part of the attempt to disrupt.

Privacy policy

On Wikimedia projects, privacy policy considerations are of tremendous importance. Unless someone is violating policy with their actions (e.g. massive bot vandalism or spam) and revealing information about them is necessary to stop the disruption, it is a violation of the privacy policy to reveal their IP, whereabouts, or other information sufficient to identify them, unless they have already revealed this information themselves on the project.

Information release

Even if the user is committing abuse, it's best not to reveal personal information if possible.

  • Generally, do not reveal IPs. Only give information such as same network/not same network or similar. If detailed information is provided, make sure the person you are giving it to is a trusted person and will not reveal it himself/herself.
  • If the user has said they're from somewhere and the IP confirms it, it's not releasing private information to confirm it if needed.
  • If you're in any doubt, give no detail.

Access to CheckUser

Only stewards, ombuds, some Wikimedia Foundation staff, and a very small number of other users are allowed to have CheckUser access. Users can only have CheckUser status locally (except for the ombuds and those staff members with access).

If local CheckUsers exist in a project, checks should generally be handled by those. In emergencies, or for multi-project CheckUser checks (as in the case of cross-wiki vandalism), stewards may perform local checks. Stewards should remove their own CheckUser access on the projects upon completion of the checks and notify the local CheckUsers or the CheckUser e-mail list.

If no local CheckUsers exist for a project, requests will need to be made to the stewards to perform checks (such as "is UserX a sockpuppet of UserY"). To do so, simply add the request to Steward requests/Checkuser listing these users and explain the need for the check (with links). Depending on the nature of the request, the steward may deny it, may ask for more information, or may answer about the likelihood of the users in question having the same IP, same proxy, same network, same country, or being completely unrelated (see discussion for what the steward should more precisely say to the editor).

Appointing local CheckUsers

On any wiki, there must be at least two users with CheckUser status, or none at all. This is so that they can mutually control and confirm their actions. In the case where only one CheckUser is left on a wiki (when the only other one retires, or is removed), the community must appoint a new CheckUser immediately (so that the number of CheckUsers is at least two).

On wikis with an Arbitration Committee (ArbCom) whose members have been elected with the support of at least 25–30 members of the local community, CheckUsers may be directly appointed by the Arbitrators. After agreement, a member of the Committee should simply list the candidate on Steward requests/Permissions.

On a wiki without an Arbitration Committee that meets the criterion above, or in a project where there is a preference for independent elections, the community may approve local CheckUsers (stewards not counting as local CheckUsers) per consensus. The candidate must request the CheckUser status within the local community and advertise this request properly (village pump, mailing list when available, special request page, etc.). The candidate must be familiar with the privacy policy. After gaining consensus (at least 70%–80% in pro/con voting or the highest number of votes in multiple choice elections) in the local community, and with at least 25–30 editors' approval, the successful candidate should request access at Steward requests/Permissions with a link to the page with the community's decision. If there are an insufficient number of votes for at least two CheckUsers on a wiki, there will be no CheckUsers on that wiki.

Mailing list

There is a closed mailing list (CheckUser-l) to which all stewards and CheckUsers should have access. Email the list moderators to gain access. Use this mailing list to ask for help, ideas and second opinions if you're not sure what the data means.

IRC channel

There is a private IRC channel (#wikimedia-checkuserconnect) to which all stewards and CheckUsers who use IRC should have access. This channel serves the same purpose as the mailing list, but in real-time. Contact any channel member to gain access; a channel manager will grant permanent access. Ask a steward if you need help gaining access.

Removal of access

Any user account with CheckUser status that is inactive for more than one year will have their CheckUser access removed.

In case of abusive use of the tool, the steward or the editor with the CheckUser privilege will immediately have their access removed. This will in particular happen if checks are done routinely on editors without a serious motive to do so (links and proofs of bad behavior should be provided).

Suspicion of abuses of CheckUser should be discussed by each local wiki. On wikis with an approved ArbCom, the ArbCom can decide on the removal of access. On wikis without an approved ArbCom, the community can vote removal of access.

Complaints of infringement of CheckUser, Access to Nonpublic Information Policy or Privacy Policy breaches are handled by the Ombuds commission for all Wikimedia projects.

Users with CheckUser access

  • Edit (last updated: 2024-11-13)

Everywhere

Arabic Wikipedia

Automatically generated checkusers list

  1. Dr-Taher
  2. Meno25
  3. باسم
  4. علاء
  5. فيصل

Bengali Wikipedia

Automatically generated checkusers list
Local policy mandates that only users who gain at least 25 votes in favor and 80% support can be appointed (applications will open for no fewer than 30 days).

  1. NahidSultan
  2. RiazACU

Catalan Wikipedia

Automatically generated checkusers list

  1. Jmrebes
  2. Joutbis

Czech Wikipedia

Automatically generated checkusers list

  1. Martin Urbanec
  2. Mormegil

Danish Wikipedia

Automatically generated checkusers list

  1. Kaare
  2. KnudW
  3. Sir48

Dutch Wikipedia

Automatically generated checkusers list

Appointed by Arbcom
  1. Daniuu
  2. Groucho NL
  3. Jcb
  4. Natuur12
  5. XXBlackburnXx

English Wikibooks

Automatically generated checkusers list
Local policy mandates that Stewards are explicitly allowed to process non-emergency CheckUser requests.

  1. MarcGarver
  2. Xania

English Wikinews

Automatically generated checkusers list

  1. Acagastya
  2. Cromium

English Wikipedia

Automatically generated checkusers list

  1. Alison
  2. AmandaNP
  3. Aoidh
  4. Barkeep49
  5. Blablubbs
  6. Bradv
  7. Cabayi
  8. Callanecc
  9. CaptainEek
  10. DatGuy
  11. Dreamy Jazz
  12. Drmies
  13. EdJohnston
  14. Ferret
  15. Firefly
  16. Girth Summit
  17. Guerillero
  18. HJ Mitchell
  19. Ivanvector
  20. Izno
  21. Joe Roe
  22. Jpgordon
  23. KrakatoaKatie
  24. Ks0stm
  25. L235
  26. Mailer diablo
  27. Materialscientist
  28. Mkdw
  29. Moneytrees
  30. Mz7
  31. NinjaRobotPirate
  32. Oshwah
  33. PhilKnight
  34. Ponyo
  35. Primefac
  36. Reaper Eternal
  37. RickinBaltimore
  38. Risker
  39. RoySmith
  40. SQL
  41. ST47
  42. Salvio giuliano
  43. Sdrqaz
  44. Stwalkerster
  45. TheresNoTime
  46. ToBeFree
  47. Vanamonde93
  48. Versageek
  49. Yamla
  50. Zzuuzz
  51. Z1720

English Wiktionary

Automatically generated checkusers list

  1. Chuck Entz
  2. TheDaveRoss

Finnish Wikipedia

Automatically generated checkusers list

  1. Ejs-80
  2. Harriv
  3. Stryn

French Wikipedia

Automatically generated checkusers list
Under the local policy, CheckUsers are elected for six-month terms.

  1. Durifon
  2. Hyméros
  3. LD
  4. Le chat perché
  5. Lewisiscrazy
  6. Linedwell
  7. Mathis B

German Wikipedia

Automatically generated checkusers list
Under the local policy, CheckUsers are elected for one- or two-year terms.

  1. Codc
  2. Count Count
  3. Karsten11
  4. MBq
  5. Squasher

Hebrew Wikipedia

Automatically generated checkusers list

  1. Barak a
  2. PurpleBuffalo
  3. TheStriker
  4. דגש
  5. יונה בנדלאק

Hungarian Wikipedia

Automatically generated checkusers list (requests and policy)

  1. Bináris
  2. Csigabi
  3. FoBe
  4. Grin
  5. Tgr

Indonesian Wikipedia

Automatically generated checkusers list

  1. Meursault2004
  2. Nohirara
  3. Ustad abu gosok
  4. Wagino 20100516

Italian Wikipedia

Automatically generated checkusers list

  1. Ask21
  2. Elwood
  3. Melos
  4. Mtarch11
  5. Ruthven
  6. Sakretsu
  7. Shivanarayana
  8. Superspritz

Japanese Wikipedia

Automatically generated checkusers list (policy)

  1. Infinite0694
  2. Penn Station
  3. W.CC
  4. さかおり

Korean Wikipedia

Automatically generated checkusers list (policy and requests)

  1. Dmthoth
  2. IRTC1015
  3. Sotiale
  4. 이강철

Malayalam Wikipedia

Automatically generated checkusers list (policy and requests)

  1. Kiran Gopi
  2. Razimantv

Persian Wikipedia

Automatically generated checkusers list

  1. Huji
  2. Ladsgroup

Polish Wikipedia

Automatically generated checkusers list
Due to a new local policy, users who gain 85% of votes in favor may become CheckUsers.

  1. Masti
  2. Msz2001
  3. Nedops
  4. Nux

Portuguese Wikipedia

Automatically generated checkusers list
Under the local policy, CheckUsers are elected for two-year terms.

  1. Albertoleoncio
  2. Conde Edmond Dantès
  3. Érico

Russian Wikipedia

Automatically generated checkusers list

Appointed by ArbCom
  1. DR
  2. Q-bit array
  3. Ле Лой

Serbian Wikipedia

Automatically generated checkusers list

  1. Djordjes
  2. Dungodung
  3. Обрадовић Горан
  4. Боки

Simple English Wikipedia

Automatically generated checkusers list

  1. BRPever
  2. Bsadowski1
  3. Djsasso
  4. Eptalon
  5. Fr33kman
  6. Peterdownunder
  7. Vermont

Slovene Wikipedia

Automatically generated checkusers list

  1. A09
  2. MZaplotnik
  3. Romanm

Spanish Wikipedia

Automatically generated checkusers list
Local policy mandates that only users who gain at least 30 votes in favor and 80% support can be appointed.

  1. Alhen
  2. Bernard
  3. BlackBeast
  4. LuchoCR
  5. Montgomery
  6. Rastrojo

Swedish Wikipedia

Automatically generated checkusers list

  1. Julle
  2. Stigfinnare
  3. Tegel

Thai Wikipedia

Automatically generated checkusers list

  1. Geonuch
  2. Just Sayori
  3. Siam2019
  4. Timekeepertmk

Turkish Wikipedia

Automatically generated checkusers list

  1. Elmacenderesi
  2. Uncitoyen
  3. Vincent Vega

Ukrainian Wikipedia

Automatically generated checkusers list

Appointed by ArbCom
  1. Andriy.v
  2. Goo3
  3. Mykola7
  4. NickK

Vietnamese Wikipedia

Automatically generated checkusers list

  1. DHN
  2. Mxn

Wikimedia Commons

Automatically generated checkusers list · (information page and requests page)

  1. Elcobbola
  2. Jameslwoodward
  3. Krd

Wikispecies

Automatically generated checkusers list

  1. Dan Koehl
  2. Faendalimas
  3. Koavf

Meta

Automatically generated checkusers list · (information page and requests page)

  1. Ajraddatz
  2. EPIC
  3. Hasley
  4. Minorax
  5. Sotiale
  6. Superpes15
  7. Vermont
  8. Xaosflux

Wikidata

Automatically generated checkusers list · (information page and requests page)

  1. 1997kB
  2. Jasper Deng
  3. Sotiale
  4. علاء


See also