Questions are being asked about the extent of Facebook's information-collection activities after a New Zealand-based developer requested his Facebook data, which included information that he had never knowingly given the company.
This included metadata about text messages that hadn't been sent via Facebook Messenger, and which the company could only have gleaned - one way or another - from other sources.
It also included "a historical record of every single contact on my phone, including ones I no longer have" and "my entire call history with my partner's mum".
That's according to Dylan McKay, a developer based in Wellington in New Zealand.
It also included metadata about every mobile phone call he had made - again, all information that McKay had not knowingly volunteered to the social media networking giant.
The claims come as more and more questions have been asked about Facebook's collection and storage or personal data following the Cambridge Analytica claims.
Downloaded my facebook data as a ZIP file— Dylan McKay (@dylanmckaynz) March 21, 2018
Somehow it has my entire call history with my partner's mum pic.twitter.com/CIRUguf4vD
McKay wrote a Ruby script, now published on Github, that could extract call metadata from the archive that Facebook prepares for users who ask for their files from the company.
Facebook is now warning users that it could take some time to prepare as more and more people demand to see the information that the company has been hoarding about them.
McKay wasn't the only person disturbed to find unvolunteered contact information in their Facebook archives, not to mention Facebook Messenger messages that were thought to have been deleted.
"I just did this and all 1500+ professional and personal contacts via my Google accounts are listed. All messages and messenger messages are there even if I deleted them on Facebook," one wrote.
The contact data from either Google or mobile phones may well be due to people running the Facebook application on their Android or Apple smartphones.
It has been known for some time that the company taps data on people's smartphones, as well as information gleaned from elsewhere on the internet - often via data embedded in third-party websites that users will be unaware of.
I just did this and all 1500 + professional and personal contacts via my Google accounts are listed. All messages and messenger messages are there even if I deleted them on Facebook.— Sugar Stone (@SugarStone2) March 23, 2018
And Facebook's tracking of users appeared to go into overdrive when it introduced its mobile app, introduced as users migrated from PCs and laptops to smartphones.
In 2014, The Atlantic noted that "Facebook wants to know where you're from, how old you are, who you're friends with, what industry you work in, your likes, your relationship status, where you vacation etc, etc in large part because marketers want to know those things".
That had followed an initiative from Facebook, ostensibly about giving users more information about the data the company keeps on them, but which also enabled Facebook to glean more information from its users.
Evil clowns, scary nurses and sharp machetes teased in autumn PUBG Hallowe'en event
Reservoir computing can achieve the higher-dimension calculations required by emerging AI
Astronomers studying first-ever reported merger of two neutron stars claim to have detect light and gravitational waves
Allen died from complications of non-Hodgkin's lymphoma