Cloudflare implements a feature that encodes your Server Name Indication (SNI). The new technology will be called ESNI.
But today, since HTTPS covers nearly 80% of all Internet traffic, SNI is leaking every site you visit online to your ISP and someone else listening to the line has become a great hole in privacy. If you know which sites you visit, you can get a very accurate picture of who you are and create both privacy and security risks.
This is a big change. Basically, it will stop using ISPs, fraudulent apps and advertising companies from collecting and selling your browsing hello. ESNI hides the identity of the websites you visit.
: Cloudflare works to make the web more personal with ESNI