Facebook’s recent controversies relating to Cambridge Analytica, consumers have been looking closer at the data Facebook collects from its users. You can take a look at all of the data Facebook has collected from you over the years at this webpage which is a lot—wall posts, photos, videos, messages and more. While it may be pretty scary how much data Facebook has from you, nearly all of it has been voluntarily provided by you. However, not all of the data it collects has been provided voluntarily, as Facebook has been scraping call log and message data from your phone for years.
The data appears to be from the Android call log and SMS metadata due to an unrestricted access to both through the “Read Contacts” permission. Only in Android 4.1 Jelly Bean was this oversight fixed so that the read contacts permission only gave access to contacts and not the call or message log as well.
When ArsTechnica emailed Facebook inquiring about their data collection, a spokesperson for the company said
The most important part of apps and services that help you make connections is to make it easy to find the people you want to connect with. So, the first time you sign in on your phone to a messaging or social app, it’s a widely used practice to begin by uploading your phone contacts.” In essence, the company says this data was used as part of its friend recommendation algorithm.
The application now explicitly asks for permissions to view your address book and call log, but even if you had denied the application access you may have inadvertently still been providing access because of how Android’s permissions worked.
If you’re curious what kind of data Facebook has collected from you over the years, download your archived data and take a look.
Source: XDA Developers