" On 18 June 2015 at 22:25, Legoktm legoktm.wikipedia@gmail.com wrote:
It's actually not useless: https://lists.wikimedia.org/pipermail/wikitech-l/2014-December/079762.html
And again, that refers to CAPTCHA used for creating new accounts, not the one under discussion.
Um, no it doesn't? It referred to *all* CAPTCHAs.
Really? It refers to "the CAPTCHA", singular, when the CAPTCHA under disussion was that for sign-ups. It also quotes:
With SUL, disabling captcha for account creation on one wiki effectively means we have disabled it on all wikis (create account on testwiki, visit enwiki, you're autocreated, edit!).
I would recommend you read https://www.mediawiki.org/wiki/Extension:ConfirmEdit/FancyCaptcha_experiments which has some more details.
So two things were disabled, and a change was noted. We don't know which of those two things caused the change. We have no evidence as to whether or not disabling the CAPTCHA *just* for (signed in) editors saving an edit would have a negative effect.