What to know about Facebook's massive outage that brought the internet to its knees

Some 3.5 billion people use Facebook's family of apps.

Facebook's global power and influence were thrust under a harsh spotlight after a massive outage disrupted services for its entire family of apps, exposing fresh vulnerabilities for the tech giant at a time when it is facing intense, renewed scrutiny from regulators and lawmakers.

The company's handful of digital platforms -- including its namesake app, Instagram, WhatsApp and Oculus -- were down for more than five hours Monday, sowing widespread confusion for the more than 3.5 billion active users the company boasts hosting across its ecosystem of internet services. The apps flickered back online Monday evening, and as of Tuesday morning all appear to be operating normally.

The rare outage, however, came at a tense time for the firm. It occurred one day before a scheduled Senate subcommittee hearing with a company whistleblower who leaked documents to lawmakers and the Wall Street Journal that suggest Facebook knew about the negative impacts of its platforms on young users. Moreover, the outage came the same day that Facebook filed a new motion to dismiss an amended antitrust lawsuit filed by the Federal Trade Commission that takes aim at the company's market dominance.

While the incident spurred a slew of memes and cheeky reactions from competitors like Twitter, Facebook's temporary absence was felt hard in parts of the world such as India and Latin America where its apps serve as digital infrastructure for vital communications and commerce.