Viewed from a certain perspective, the 50 million accounts breached at Facebook in late September seem insignificant: They represent only a fraction of the platform’s 1.47 billion daily users.

But that 3 percent figure fails to account for the potential fallout from lawmakers, regulators and Facebook account-holders themselves in the aftermath. The breach, while already patched, occurred amid growing scrutiny of the kinds of information that American businesses — particularly those in the multi-billion-dollar technology industry — gather, how they use it and how well they protect it.