What's (to me) much more exciting to me is the incremental local backups they're working on. I've iirc looked into how to decode these big backup files, and copy them off my phone semi-regularly, but this being rsyncable will make the process much faster
Even if it works for desktop clients also, that still needs to be set up using a data matrix scanned by the mobile device (or if that's already done before you lost the origin device, you can "simply" extract the faux-encrypted sqlite format that the desktop client uses, albeit with having to recompile this encryption extension for Sqlite manually — ask me how I know..)
For storage platforms like Dropbox or Onedrive, it can be as simple as ctrl+c'ing the data out of there every now and then
For Spotify, you can do the GDPR export and check that you can open it somehow. Even if it's not super readable, you can figure that out (with a tech friend or LLM perhaps) if you turn out to ever need it
For Signal, I've got no idea. The format is hard to work with for hardcore techies. They really really don't want you, ahem, attackers to get that data in the clear. (Two-sided coin). Make sure to turn on the backups, write down the passphrase, and take them off your phone every now and then, and hope there's a restore method when you need it
The only reason I can imagine why nobody implements this, is that they like the status quo where it's hard to switch to their service, but equally hard to switch away. Once this becomes commonplace (e.g. because vendor A makes users aware it's a thing by implementing it for migrating from vendor B), vendor B will "retaliate" and A will have to truly be better than vendor B to retain said users
That is all to say, this might yet totally be a viable and legally unblockable business avenue for a third party to initiate. I'm just not sure there's enough demand to warrant (read: pay for) the effort involved. Maybe if you can have an LLM read the api docs of the service where you want to do the import and autogenerate a mostly-working version?
It's also ironic that we're considering docx etc as open formats these days.
The usual rule when making backups is that you need 3 copies, one of them offsite. A cloud storage service counts as an offsite copy, but you still need two more, typically one on your computer and one in cold storage (ex: external hard drive).
Treat cloud storage like you treat your hard drive, it can fail at any time. The failure modes are different: mechanical failure vs losing access to your account, but the end result is the same: the system is unreliable and you have to engineer around it.
When people want off-site backups, the server owner can say they've already taken care of that. I'd say that having a copy under your own control is a separate checkbox we should include!
The third backup being in a decoupled system on site is what you now count as your ”offsite” backup. Having this last copy is non-negotiable, no matter how many 9s S3 claim to have.
Wait what, how does (did?) that work?
And more importantly (I can find the opus files myself): can/could it retrieve my account data to know which songs to download?
I've been able to partially reconstruct my music from localStorage, downloaded songs on my phone (yay for having root and access to that data folder), and memory, but it's still incomplete
Fwiw, here's my own little contribution to getting song data from Grooveshark, in my first blog post: https://lgms.nl/blog-1 (not my first blog site though). Happy to meet other fans :D
Maybe Spotify won't be taken down overnight, but they can lock me out for various reasons such as misdetecting an IP address (Google wouldn't let me log in at all when they thought I was in Russia, when I was at 31C3 in Hamburg, Germany, a conference where they afaik use some temporary IP space — I don't know what consequences that would have nowadays)
Hacker News also: if there are things here you want to keep, store them yourself
Facebook chats, Signal, etc.: download the data in a format you can decode if there's anything you want to keep. Make sure you can decode this Signal backup format if your phone dies