Update: It appears that the whitelist is not preventing the arithmetic CAPTCHA. I will contact Jetpack support for more information.
Those of you logging into the admin area of sites on our WordPress network may have been repeatedly asked to “prove your humanity.” This is a feature of the Jetpack plugin suite that helps protect against brute force login attempts.
“Human” users would have to solve an arithmetic problem and enter the answer in a tiny box. This tiny box was easy to miss, so multiple failed attempts to log in would add up, and the username trying to log in would be temporarily locked out.
I have added all Princeton University IP addresses to the whitelist settings for the Jetpack Protect feature, so in the future, you should only encounter this test of your humanity when logging in from an outside network.