Why does google tell me to spell certain words while signing in?

I put in my email and password, but it tell me to type blabber in the box below and telling me to re-enter my password, and I don't know why!

Welcome to Android Central! It sounds like Captcha, or something similar, to improve security and make sure you're not a bot. When are you seeing this? Is this within an app or on a website? Show us a screenshot of what you see: http://forums.androidcentral.com/gen...d-central.html. You'll need to register on this forum first.