WIRED
Still smarting from last month’s dump of phone numbers belonging to 500 million Facebook users, the social media giant has a new privacy crisis to contend with: a tool that, on a massive scale, links Facebook accounts with their associated email addresses, even when users choose settings to keep them from being public.
A video circulating on Tuesday showed a researcher demonstrating a tool named Facebook Email Search v1.0, which he said could link Facebook accounts to as many as 5 million email addresses per day. The researcher—who said he went public after Facebook said it didn’t think the weakness he found was “important” enough to be fixed—fed the tool a list of 65,000 email addresses and watched what happened next.