An almost throwaway sentence in the paper stood out to me:
>Because transactions take place at well-defined geographic locations and at well-defined moments in time, intersecting the IMSIs of SIM cards present near the crime scenes immediately revealed the perpetrators’ SIM card details.
>Because transactions take place at well-defined geographic locations and at well-defined moments in time, intersecting the IMSIs of SIM cards present near the crime scenes immediately revealed the perpetrators’ SIM card details.