Several Facebook users who downloaded some of their data from the social network after its scandal Cambridge Analytica have discovered that mobile social networking applications record in some cases much more information than they expected.
The recorded information includes data on all phone calls made to the phone, the time of each call, its duration, and the name of the contact. The Facebook app does not record phone calls to and from numbers that are not in the phone's address book.
The application is reportedly also gathering information from all SMS messages sent or received by the device. But again, it does not record SMS data from numbers that are not in the address book of the phone. Facebook does not record the actual text of the SMS.
SMS and SMS storage behavior was confirmed by many users on Twitter, Reddit and HackerNews, as well as an ArsTechnica journalist.
The reason why this behavior was observed is now due to the Facebook-Cambridge Analytica privacy scandal that broke out last weekend. After the announcement, many users decided to disable or delete their profiles on Facebook.
During the deletion process, users can download a backup of all Facebook's collected data for them.
This is the same data that users can download by clicking on: "Download a copy of your data" added to the page with the basic settings of your account in Facebook.
Facebook does not record SMS calls and metadata by default. This information is only collected by certain profiles.
What are these;
The data is only collected by users who have allowed the Facebook app to "see" the contact list to discover Facebook friends using the contact list phone numbers.
Downloaded my facebook data as a ZIP file
Somehow it has my entire call history with my partner's mum pic.twitter.com/CIRUguf4vD
- Dylan McKay (@dylanmckaynz) March 21th 2018
At the moment, however, it is not clear why the Facebook application records the metadata from phone calls and SMS messages, as all the data needed to find friends is just the contact list.
One “theory” is that Faceboook collects this information in an attempt to identify with whom the user maintains the most contact to prioritize this person's publications.
Of course, if this data is added to the big data on the social network, they can add extra information about how your person moves in and out of the service.
One of Twitter users who saw this strange behavior from the mobile app created one Ruby script which analyzes Facebook's backup file and generates very good summaries.