Gooogle are being totally dishonest and misleading in their use of reCAPTCHA to digitize house numbers.

"reCAPTCHA is a free CAPTCHA service that helps to digitize books, newspapers and old time radio shows."

"Currently, we are helping to digitize old editions of the New York Times and books from Google Books."

They are lying and they are not benefiting the public interest - which is what reCAPTCHA relies on - they are only benefiting their company and their own shareholders.