Last year, Facebook was forced to admit that after months of pestering its users to switch on two-factor by signing up their phone number, it was also using those phone numbers to target users with ads. But some users are finding out just now that Facebook’s default setting allows everyone — with or without an account — to look up a user profile based off the same phone number previously added to their account.
The recent hubbub began today after a tweet by Jeremy Burge blew up, criticizing Facebook’s collection and use of phone numbers, which he likened to “a unique ID that is used to link your identity across every platform on the internet.”
Although users can hide their phone number on their profile so nobody can see it, it’s still possible to “look up” user profiles in other ways, such as “when someone uploads your contact info to Facebook from their mobile phone,” according to a Facebook help article. It’s a more restricted way than allowing users to search for user profiles using a person’s phone number, which Facebook restricted last year after admitting “most” users had their information scraped.
I’ve never given my phone number to any social media site. If that means someday I get permanently locked out of my account, so be it.