> So essentially they asked for anonymised lists of phones (i.e. not even the actual numbers) that had been in the locations where the suspects had been, then c

> So essentially they asked for anonymised lists of phones (i.e. not even the actual numbers) that had been in the locations where the suspects had been, then cross-referenced these to find potential suspects, presumably finding some phones that exactly matched the reported movements of the suspects which they then made a second application to de-anonymise. In what conceivable way does that count as an "anonymised list?" Suppose Google happens to sell geodata for everyone in your area of town to a third-party. Are you reassured if they tell you, "It's ok, we removed your phone numbers first."