Role-specific information: CheckUser policy
As you likely know, the CheckUser policy applies to users with CheckUser permission. This permission is mainly limited to stewards, ombudsmen, and WMF staff. Wikimedia projects may also have local, stand-alone CheckUsers.
Broadly speaking, CheckUsers can view certain PI such as user IP addresses and user agent information. Pursuant to WMFs Data Retention Guidelines, such checks may generally be conducted for the previous 90 days of site history before the relevant data is deleted from WMF’s servers.
The tool exists to fight vandalism, check for sockpuppet abuse, and to limit disruption of the Wikimedia projects. It should not be used for any other reason. Examples of unacceptable reasons include:
- political control;
- applying pressure on editors; or
- threats against editors in content disputes.
Consistent with the access to nonpublic information policy and confidentiality agreement, nonpublic PI obtained via CheckUser permission, such as IP addresses or user agent information, should not be disclosed unless a valid exception applies.
Please also note that the CheckUser policy cautions against revealing PI even where a valid exception does apply. Where possible, it recommends revealing information such as “same network/different network” rather than a specific IP address.
Notifying a checked user that their information has been checked is optional. You also have the option of notifying the communities that user information has been checked, in cases where you do not disclose PI or a valid exception applies.