Using HSTS and browsers pre-loaded list of sites that are HTTPS-only prevents leakage: https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security https://en.w

Using HSTS and browsers pre-loaded list of sites that are HTTPS-only prevents leakage: https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security Also cookies also have a 'secure' flag.