Facebook set up a website that its 2 billion global users can use to check if their accounts have been accessed, and if so, exactly what information was stolen. It will also provide guidance on how to spot and deal with suspicious emails or texts. Facebook will also send messages directly to those people affected by the hack.
On that page, following some preliminary information about the investigation, the question “Is my Facebook account impacted by this security issue?” appears midway down. It will also provide information specific to your account if you’re logged into Facebook.