

I worked tech support for an ISP, and i did this more often than i want to think about it.
It didn’t help that one of the cable modems we gave out to our clients had a standby-button, which made the CM look like it was off - there was no indicator at all on the device, so i couldn’t even blame the client for that (but i did blame my employer for not thinking about that. just like i blamed him for buying another modem series with power sockets which failed pretty quickly. did i mention that repairs were done in-house, and not all too well? it’s been 20 years, and i am still a bit salty for all my wasted time)
private.coffee is the address of a server belonging to a privacy focused NGO, who offer all those services, including RedLib, for the general public, regardless of where they come from. They are not affiliated with the fediverse or anyone else.
There are many servers hosting RedLib, all offering the same functionality, to help to preserve the privacy of users worldwide. RedLib itself comes with a variant of the GPL, a licence which gives everyone the right to host a RedLib-service; if you wanted, you could run it on your own computer, or you could rent a server and host it there, offering the same service for others.
This is similar to lemmy - you can rent a server, a domain (like private.coffee or lemmy.world), and host a lemmy instance for yourself and whoever you wish to share the service with. Your Lemmy instance would then talk to other lemmy servers worldwide and share posts and comments with them - this exchange between different Lemmy Instances is called “federation”, and it means that no single person can decide how lemmy is run, because everyone can only control their own server. Lemmy also federates with other services, like Mastodon or Misskey, since all those services talk the same language: ActivityPub.
I hope i could be of assistance; if you have any more questions, feel free to ask!
Have a nice day!