Hi,

Just i forget my facebook account password and want to reset it. So i go to facebook website and then forget password and then trying to enter the Security Check words like the below screen shot

Because I am a developer, I can guess the technical problem as the function which compare the user input  and security check words is wrong .

After you click Reset password, FB will send you an email with code to change your password despite of wrong input words as shown on the above image.

May be The below is the technical problem expectation
            The below function of validating word will ignore the last character.

I like catching the problems from big companies’ products :)

Hope it being nice post for you.!