Dave Troy 
Another design consideration re: Mastodon is that it works well for ephemeral asynchronous communications, but for many reasons should not be counted on as an archival resource. Media attachments are periodically purged and may not be available after a week, or a month, etc. While some servers may try to preserve content forever, this may be costly and unsustainable. Creators, researchers should treat this as an ephemeral resource and make provisions for self-archiving anything important.
This said, it’s likely that individual ‘home’ servers will preserve its own users’ content longer than those it pulls from federated servers, but even that can’t be relied upon indefinitely. Point being, assume this is an ephemeral resource, even as it’s a pretty decent one that may appear persistent for most practical use cases. Obviously, any given server can also disappear overnight, for any reason, so behave accordingly.
Xabier Ostale@davetroy The important issue is that the conversation goes on. That's the priority, I guess.