Anonymizing user location data in a location-based application

A non-transitory computer-readable storage medium comprising instructions executable by a processor, the instructions executable to perform operations comprising:

• receiving location data from a client device associated with a user of a location-based application;
• hashing a player identification (ID) associated with the user;
• writing location information, derived from the location data, and the hashed player ID to a first retention table, the first retention table being a short-term retention table storing the location data for a first geographic area of a first size and for a first retention period, the first retention table storing location data indicating a longitude and latitude of the client device;
• responsive to determining that the first retention period has expired, anonymizing the location data and transferring the anonymized location data to a second retention table, the second retention table being a medium-term retention table storing location data for a second geographic area that is larger than the first geographic area and that incorporates the first geographic area, the second retention table storing location data indicating a city block on which the client device is located, wherein the second retention table has a second retention period;
• deleting the location data from the first retention table;
• responsive to determining that the second retention period has expired, anonymizing the location data and transferring the anonymized location data to a third retention table, the third retention table being a long-term retention table storing location data for a third geographic area that is larger than the second geographic area and that incorporates the second geographic area, the third retention table storing location data indicating a city in which the client device is located, wherein the third retention table has a third retention period;
• deleting the location data from the second retention table;
• and
• responsive to determining that the retention period for the third retention table has expired, causing the location data to be deleted from storage.