Facebook has admitted that the phone numbers that its users provide for security purposes are being used to target them with ads, the media reported.
"We use the information people provide to offer a better, more personalised experience on Facebook, including ads," a Facebook spokesperson was quoted as saying by TechCrunch on Thursday.
The social network specifically uses a phone number that users provide for two factor authentication (2FA) – a security technique that provides a second layer of authentication to help keep accounts secure, the report added.
Facebook confirmed the use of users' phone number for targeting ads after Gizmodo reported research work carried out by academics at two US universities who found that the social network uses pieces of personal information that individuals did not explicitly provide it to target them with ads.
"We are clear about how we use the information we collect, including the contact information that people upload or add to their own accounts. You can manage and delete the contact information you've uploaded at any time," the Facebook spokesperson said.
Besides using the contact information users willingly provide to Facebook, it is also using contact information they handed over for security purposes and contact information they did not hand over at all, but that was collected from other people's contact books, the Gizmodo report said.
The findings of the study suggest that Facebook uses "shadow contact information" to make money through advertising.
This revelation hardly comes as a surprise, with many expecting the social media giant to make the best use of other products like WhatsApp and Instagram, to boost its coffers.
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