I stumbled upon a revelation of sorts yesterday. See, I was under the erroneous impression that the fingerprint data was being stored on the hard drive somewhere; probably locked away like the root user’s (and other users’) login data. And, thus, it would be wiped out whenever the hard drive was wiped and a new OS installed.
Instead, I have discovered that the fingerprint reader has its own, separate, non-volatile memory where it stores the fingerprint data. Because this data is preserved between reboots (non-volatile), it is also still full of fingerprint data even when the hard drive is wiped and a new OS is installed.
This explains why there are so many posts here about how to delete the fingerprint data. After all, if the fingerprints were stored with Windows, Ubuntu (or any other OS) doesn’t know about it; I guess it cannot read that data because maybe it’s stored in a different format. I don’t know. In any case, this completely explains why I was unable to register (enroll) any new fingerprints after the first set when I first installed Ubuntu and things went awry with it.
Also lending credence to this is the fact that the fingerprint reader’s memory is extremely limited. From what I can tell, it can only store 5 fingerprints. Attempting to store a 6th fingerprint results in the dreaded “Fingerprint device disconnected” message in Ubuntu.
This is all based on my own testing with this particular fingerprint reader. I’m sure other fingerprint reader brands and models may store more (or fewer) fingerprints, but that’s not relevant to this thread about the Framework’s reader. If any of this information is wrong, please correct me, as I am clearly not a fingerprint reader expert; Many of you know much more about them than I do.
Finally, I’d like to apologize for coming across as rather rude in my posts. Not only do I have a tendency to do that in general, I was in a particularly bad mood recently and I should not have let it bleed into this thread.