The FTC hasn't commented on the apparent leak, although any probe would likely take a significant amount of time for the agency to reach a definitive conclusion.

If the trade regulator does get involved, it'll join a slew of state-level, UK and European Union investigations. Members of Congress want answers, too. Facebook is scrambling to deal with the scandal on its own terms, but it may be too late for the company to avoid serious legal repercussions -- especially when it reportedly knew about the data sharing in 2015.