Apple via Press Release:

This data is not the iPhone’s location data—it is a subset (cache) of the crowd-sourced Wi-Fi hotspot and cell tower database which is downloaded from Apple into the iPhone to assist the iPhone in rapidly and accurately calculating location. The reason the iPhone stores so much data is a bug we uncovered and plan to fix shortly (see Software Update section below). We don’t think the iPhone needs to store more than seven days of this data.

So the location database people found was not actual locations that the person traveled to, but data that Apple pulled down from its WiFi and cell tower database location cache. Interesting, what really made me do a double take:

Can Apple locate me based on my geo-tagged Wi-Fi hotspot and cell tower data? No. This data is sent to Apple in an anonymous and encrypted form. Apple cannot identify the source of this data.

So Apple is not collecting data from the database file people found, but from another source which is anonymized, encrypted, and sent to Apple. I want to know more about this.