If you have ever heard of IRC it uses that network to directly send files to you. Basically you need an IRC client then you message a bot for the file(s) you want it to send to you. There are xdcc search engines like sunxdcc and you can usually find books, audio, anime, etc.
Its an old school chat protocol. You can try it for yourself kiwiirc is a website that lets you chat with IRC. You need to pick a network, Rizon is a good network to start with. There are a bunch of different commands you can use but the only ones i found useful are /msg to send a message and /join to join a channel.
For the downloading part you need a client that supports XDCC, and then you can use these commands with your bot of choice
Oooh so it's my first time hearing and after looking it up, WHY AREN'T PEOPLE USING IT?
Like why pay for a VPN, when you have stuff like this?
What are the limiting factors for XDCC?