Nearly 1.5 billion people worldwide use Facebook. That’s roughly in line with the number of Android devices and Windows PCs in use, and somewhat larger than the billion-odd iOS devices ever sold. Facebook isn’t an operating system, even though it’s a platform: It’s a base on which Facebook pushes out its own software and other parties develop and deploy apps that run on the Facebook infrastructure.
Thus, the decisions it makes have broad repercussions, especially because its users cut across every operating system and browser, through native and web apps. Facebook sits at the juncture of two significant technology challenges, which have roots years in the past, and which both threaten the safety and security of Internet users.