Mobile carriers often offer limited bandwidth, which encourages individuals to use public hotspots, whenever available.

Due to the on May 2018 applied European General Data Protection Regulation, the providers of these hotspots are required to get the users' consent to process their data. However, it is not clear what type of personal information is collected in return to free internet access. 

This work requires the student to travel in Germany, and collect privacy policies of hotspot providers to analyze their content. Also, some familiarity with Wireshark is required to capture the Internet traffic while connecting to a hotspot. 

Also see https://www.pcworld.com/article/3315197/free-wi-fi-hotspots-can-track-your-location-even-when-you-arent-connected.html