If you visit the URL google.com/foobar it won't do anything unless your google account has been offered the challenge. Presumably random searching wouldn't even

If you visit the URL google.com/foobar it won't do anything unless your google account has been offered the challenge. Presumably random searching wouldn't even activate it, you'd need to be in the right country etc. "To log in, you have to have logged in before. Confused? Search on...[google.com]"