Yes, and I mostly agree. Most companies just randomize an ID or do some group-bys and consider it "anonymized", which are susceptible to a variety of correlatio

Yes, and I mostly agree. Most companies just randomize an ID or do some group-bys and consider it "anonymized", which are susceptible to a variety of correlation techniques (such as setting up this MILP problem). And the more data sets you have with the same underlying masked primary key (e.g. person), the easier it can get. I have seen these weak attempts at hiding information in multiple industries. Just for the record, in my use case there was never an intent to map data to individuals, just to get the most granular information possible about key metrics.