In Germany police went around and even looked at contact tracing lists (on paper) in restaurants [1]. Even while politicians still stated publicly that these lists were only used (or to be used) for contact tracing.

[1]: https://www.golem.de/news/hamburg-polizei-nutzt-corona-konta...

Also the partly state sponsored luca app (check in in locations, festivals, restaurants, concerts) that is privately developed (and riddled with security holes) is already in discussion to use the data on the people to better target them for concert tickets and the like [2].

[2]: https://www.ccc.de/de/updates/2021/luca-app-ccc-fordert-bund...

So we see this data is already in abuse by the state and also by state sponsored private entities.

I believe, that this data, once collected, will only be (ab)used further in the future. In my experience it will be as with all data caches - somebody wants to create additional value from it.

Singapore:

https://fortune.com/2021/02/01/singapore-covid-data-tracetog...

https://www.straitstimes.com/singapore/politics/police-can-a...

https://www.straitstimes.com/singapore/proposed-restrictions...

https://www.straitstimes.com/singapore/politics/bill-limitin...

(Note that one mostly-united political party controls 89.2% of Singapore's legislature seats, and can pass any laws or amend its constitution to their liking.)