Ignore This Okay

I heard from /b/ that there was a hidden text field with the words IGNORE THIS OKAY next to them. What does this do and why should it be ignored?

sigh... goddamn newfags. the textfield was put there by moot in 2006, because too many people were begging to get banned from 4Chan, as they were too addicted. If you enter anything into the box you geta erma ban.