Nice, I think they did something similar in China.

Cherry on top of the cake would be to provide an app, where people could voluntary agree to anonymous location tracking and for their COVID-19 status to be updated by health authorities (or themselves in case they already know).

Having that, I think it wouldn't be too complicated to alert other potentially not infected people that someone that has been exposed to the virus was nearby.

Once someone was diagnosed as being infected, would could taint and steralize all the locations this person visited in the X number of days prior.