I assume the reader stores all results along when log of when it was accessed. Therefore it would not be hard to require anyone with a prescription to come in and see the nurce every few weeks to explain what actions they have taken based on their BG data.
(I don't understand why they don't check meters to see if people are using all the test strips they are presribed, hence stopping reselling of them.)
PS you don't need a private prescription to get a libre, as you can just order one yourself direct.