Facebook Whistleblower Calls for New Tech Laws in Europe

LONDON— Facebook Inc. whistleblower Frances Haugen encouraged U.K. lawmakers to pass legislation to rein in social-media platforms, saying that Facebook has trouble curbing misinformation and hate speech in many languages and dialects, including British English.

Ms. Haugen’s comments to a U.K. parliamentary committee Monday give new impetus to the biggest potential expansion in global tech regulation in years, with Britain currently considering legislation to curb harmful online content. The former Facebook employee presented her conclusions from a set of internal Facebook documents—first disclosed in The Wall Street Journal—that she says illustrate the social-media company’s struggles to balance the safety of its users with its own profit motive.