Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
Google Sign-In is a secure authentication system that reduces the burden of login for users, by enabling them to sign in with their Google account.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.