While it could be considered as secure in data transfer (data goes to the organisation/business which has set up the QR code), once it arrived to the organisation who collected it, it isn’t very private and the organisation/company can potentially use the data as it sees fit.
QR codes are discussed at the end of these two threads:
Simple answer yes. The above threads provides links to privacy groups and this is one of the main issues which has been raised. A organisation/business can use the contact data for marketing or pass it onto a second or third party for their use very easily.
A better way maybe for the government to issue unique QR codes to every potential contact point and this QR code location data, time stamps and personal information is only supplied to the government (businesses/organisation don’t receive the data which is currently the case). The government then processes the data for contact tracing when a case is identified. Unfortunately we live in the real world.
As sample number 2- no. This might be because use of QR codes isn’t mandatory in Tasmania and we chose the old fashion pen and paper instead.
