Commons & Wikidata material (& to a lesser extent Meta) gets grandfathered in to local projects, and the local admins have no means of checking that material once it has been deleted from its home wiki.
Material on Commons is requested for deletion as advertising. By the time the Commons admin sees the request the local wiki's article/draft which contained the image (showing it to be clearly advertising) has been deleted and that context no longer exists.
Sockpuppetry is a cross-wiki problem. Checkusers are restricted in what they are permitted to investigate. Evidence needs to be acquired before Checkusers can act. If the sockpuppets are active cross-wiki, those users trying to investigate need access to the cross-wiki evidence.
Cross-wiki spamming is often trackable through the shared wikidata item. If that gets deleted, the evidence is broken up.
The ability to verify cross-wiki should also improve mutual confidence between wikis and reduce inter-wiki NIMBYism.
It is proposed to create a global permission, global admin view which may be requested at meta by admins from public-facing wikis (i.e. not the test or development wikis). It would allow on ALL public-facing wikis without the opt-outs which restrict global sysops :-
View deleted history entries, without their associated text (deletedhistory)
View deleted text and changes between deleted revisions (deletedtext)
Candidates for this permission should be acceptable across wiki projects. To this end:
The user must have held permanent (not temporary) sysop permission on their home wiki for at least 3 months before applying. They must have acquired their sysop status by being elected with the support of at least 25–30 members of the local community.[Notes 1]
The user should not be blocked on any WMF project.
The permission should be requested at m:Steward requests/Global permissions with no fewer than 2 weeks of discussion. This is the same requirement as requests for global renamer and global sysop. The purpose is to establish that the user is trustworthy across projects.
On the loss of local admin rights. This will need coordination between local bureaucrats & stewards.
On being blocked on any local project. It's not supportable that someone should see deleted content on a wiki on which they are blocked. This will need coordination between local sysops & stewards.
For misuse, e.g. using the ability to see deleted material to restore the material to public view on any WMF project out-of-process under the same or another title.
On request of the user.
As the permission does not include the potential to act, just to see, there are no activity requirements.
