@PavelVoronezh
> the ability to back up data on one of the friendly servers
Have you looked into the Zot protocol and its Nomadic Identity? It does exactly that. Of all the fediverse software I'm aware of, only Hubzilla and Streams implement Zot. I'm pretty sure Zot apps could already do this when ActivityPub was being drafted. Not sure why this capability wasn't included in AP