Facebook recently asked users to add their phone numbers to their profiles as an extra security measure, but now users have realised their numbers are being used as a way to look up their profiles and target them with ads, and there’s no way to turn it off, according to users.
As TechCrunch reports, the issue was raised after Jeremy Burge, the founder Emojipedia, tweeted about the feature last Friday (March.1st).
“For years Facebook claimed that adding a phone number for 2FA was only for security,” he wrote. “Now it can be searched and there’s no way to disable that.”
Facebook ‘look-up option’
Facebook does allow users to hide their phone numbers from the general public and restrict their settings to friends on their profile. However, there is no way to get rid of the look-up option entirely as the option is set to default.
That means if a user’s settings are set to ‘Everyone’ instead of ‘Friends of friends’ or just ‘Friends’, anyone can view their page on the site, even if they don’t have a Facebook account.
Burge also goes on to point out that phone numbers could also be used as a way for different companies to link people’s activity across a variety of different platforms, allowing people to be tracked across the web.
“Using a phone number to sign up for services has been the single greatest coup for the social media and advertising industries. One unique ID that is used to link your identity across every platform on the internet,” he wrote.
“That is why every start-up wants your phone number.”
The concern surrounding Facebook’s use of phone numbers comes after the company announced plans to further integrate its messenger services across Messenger, Instagram and WhatsApp.
WhatsApp uses phone numbers as a primary way to set up an account, which could raise privacy concerns for users that use the app.
A Facebook spokesperson told TechCrunch that the settings are “not new” and “the setting applies to any phone numbers you added to your profile and isn’t specific to any feature”.
Since May 2018, Facebook removed the requirement of adding the feature to set up two-factor authentication (2FA).
In September, Facebook told TechCrunch that it uses phone numbers provided for 2FA for ad targeting after Gizmodo reported that numbers provided for 2FA “became targetable by an advertiser within a couple of weeks”.
Alex Stamos, former chief security officer and now an adjunct professor at Stanford University, also called out the practice in a tweet. “Facebook can’t credibly require two-factor for high-risk accounts without segmenting that from search and ads,” he said.