Anti-bot CAPTCHA widget from Google.
https://www.google.com/recaptcha/intro/index.html
Widgets · CAPTCHA
Get access to data on 9,950,572 websites that are reCAPTCHA Customers. We know of 2,000,001 live websites using reCAPTCHA and an additional 7,950,571 sites that used reCAPTCHA historically and 1,297,304 websites in the United States.
Get a list of 9,950,572 websites using reCAPTCHA which includes location information, hosting data, contact details, 2,000,001 currently live websites and an additional 4,163,206 domains that redirect to sites in this list. 7,950,571 sites that used this technology previously and 1,297,304 websites in the United States currently using reCAPTCHA.