Board Thread:Support Requests - Community Management/@comment-5343891-20121223034156/@comment-168424-20130112091537

Ozank wrote: Special:ProtectSite has the option to disable anonymous editing, however it is used for anti-spam/vandalism reasons and not every wiki has it. (Those wikis who get a lot of vandalism can have it enabled)

As far as I know, Special:ProtectSite disables all non-admin editing and is not comparable to disabling anonymous edits. Also, it would never be enabled long-term.

As an admin who has worked on wikis of all sizes and some that don't allow anonymous edits, I think the argument against disabling anonymous edits is weak and mostly because Wikia thinks even bad traffic makes it money.