Fingerprint removal deletes prints stored on the reader
Pull request 16403, merged into quattro, deletes a user's prints on the reader with fprintd-delete before the local files go. A match-on-chip reader keeps each enrolled print on the device as well as in /var/lib/fprint.
That reader is a Mac's Touch ID, and some Synaptics and Goodix USB readers. fprintd only finds the device's copies through the local records, so once those records are gone nothing can delete the copies on the reader.
Removal asks for sudo first. A refusal stops it before anything changes. A missing reader is reported as "No devices available", and without fprintd the delete is skipped.
The press and touch-or-swipe lines fit in 80 columns. They were up to 125 characters, and the setup terminal wrapped them mid-word on a MacBook Neo.