The personal information of close to 270 million Facebook users was exposed for a week in December.

A database with the Facebook IDs, names, and phone numbers of 267 million users was posted online on December 12th. The database was discovered by security researchers.

The information was posted in a hacker forum and was available for download for a full week before the company that was hosting the file removed it after being contacted ty the security researchers.

This doesn’t necessarily mean the Facebook accounts were hacked. It’s possible that the person compiling the data simply used already publically available data and compiled it together in one database.

Why put together the data? That kind of data is extremely useful in creating phishing emails or messenger scams where you pretend to be a friend of the person you’re contacting. Phone numbers are handy for targeting text message and phone scams as well.

Since there’s no evidence of an actual Facebook breach, people whose names and numbers were posted won’t even know it happened to them. The best advice for everyone is to always be on the lookout for suspicious emails, friend requests, and messages. And to make sure you keep information like your phone number private on Facebook.