Depends on your definition of "the data". If they store all the data, split it in two, and you only count one half as "the data", and the other half as... somet

Depends on your definition of "the data". If they store all the data, split it in two, and you only count one half as "the data", and the other half as... something else, then yes, it can be both anonymized and de-anonymizable. But I think privacy advocates (myself included) count everything collected and stored as "the data", and don't find some red tape securing it particularly reassuring.