In the wake of revelations that the data of 87 million users was exposed to political consulting firm Cambridge Analytica, Facebook CEO Mark Zuckerberg will testify before Congress under oath. A notoriously awkward public speaker, Zuckerberg’s primary battle may be to “ stay on script while keeping his armpits dry ,” writes Slate senior technology editor Will Oremus. He joined Marcie Sillman to discuss what we can expect from this week’s hearings, and what Facebook might be afraid of.