Facebook has a user-base that today is only less than the population of China and India. The systematic break-in as appears to have taken place into FB could have compromised 50 million accounts and that's very worrying. This is because despite the fact that Facebook led the social media charge in devastating the professional media industry as it became the single-point source of information for many people, it is precisely for that reason if Facebook is compromised it could potentially be used to manipulate democracy and news flow across the world.
While no computer security system is safe, and Facebook was proactive in identifying and rectifying the issue, it should remain a cause for concern. With the company also fighting regulations across the world, such issues are rarely brought to the attention of the authorities. That should change, as Facebook is today far too powerful to be managed by a group of Ivy-League educated managers and engineers.