Today, every operation that required captchas failed on every WMF project with a "Ran out of captcha images" exception. After being informed of it, I disabled Swift storage for captchas[1][2] after which everything returned to normal. The problem persisted from 8:21 to 10:58 UTC.
--- [1] https://gerrit.wikimedia.org/r/40351 [2] https://gerrit.wikimedia.org/r/40352