Prescription histories are already available for purchase.
All I know is that there are at least three hedge funds with the ability to acquire individualized prescription histories. I don't know if they are able to "deanonymize" guids in a large database, or if they query based on the individual.
Congress should start asking questions.
There are many companies that offer the data for sale. The example I link seems to require HIPAA authorization from the individual, but the authorization is not actually required by law. It also raises the question how the vendor is able to acquire the data without HIPAA authorization.
The data is advertised as "real time".
For what it's worth, my money is on "deanonymizing" guids. Hedge funds want to track sales in real time to have an edge in earnings forecasts.
(Or whether what they’re doing is borderline legal to begin with)
Yes it will! Because then other people can confirm your claims.