Do any popular sites or services have them? Most internet forum and social network social you can setup don't. Nor do Facebook, Twitter, Instagram, Reddit, YouT

Do any popular sites or services have them? Most internet forum and social network social you can setup don't. Nor do Facebook, Twitter, Instagram, Reddit, YouTube, LinkedIn, etc. Honestly, unless you're using a system that specifically markets itself on this (Signal, Telegram, etc), you probably shouldn't expect any encrypted communications.