A trace comprising location data about a computing device is received at a mapping server, where the trace stores the location data about the computing device in an ordered set of points. The origin and destination of the trace are obscured. Then, the trace is then separated into a set of subtraces by dividing the received points of location data into a set of subtraces, and removing the links between subtraces of the set of subtraces. For example, subtraces can be divided based on size, distance, elapsed time, or features of interest present in the location data.