Captcha when logged in

Question

I'm logged in and just submitted an answer to a question on the main site... I was redirected to a Captcha screen asking if I was human.

My issue on this page is the screen didn't show the actual Captcha phrase or input field. It just showed the robots at the top and an "I Am Human" button. I used the back arrow in my browser to return to the question page and clicked again to submit my answer... this time it posted without the Captcha page.

My question is why am I seeing a Captcha page as a logged in user?

Answer 1

We use captchas partly as a rate-limiting tool. Just because someone is logged in, doesn't mean they're not necessarily running a bot or a script either on purpose or due to a compromised account.

Ideally you shouldn't see a lot of these, but they do periodically pop up even for high-reputation users and moderators.

You can read more about how and when we show captchas here: How often do CAPTCHAs appear?.