Facebook says 50 million user accounts have been affected by a security breach.
The company says hackers exploited the “View As” feature on the service.
Facebook says it has taken steps to fix the security problem and alerted law enforcement.
To deal with the issue, Facebook reset some logins, so 90-million people have been logged out and will have to log in again.
That includes anyone who has been subject to a “View As” lookup in the past year.
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