A New Zealand-based programmer shows how he found his year-old data in an archive he downloaded (as a ZIP file) from Facebook. Facebook was collecting this data on its users from last few years, which was even reported earlier in media. In older versions of Android when permissions were a lot less strict, the Facebook app took away contact permission at the time of installation that allowed the company access to call and message data automatically. If you don’t want Facebook to store or continuously upload your contacts to its server, you can turn off continuous uploading setting in the Messenger app.
Source: https://thehackernews.com/2018/03/facebook-android-data.html