The Department of Justice, through its Office of Immigration Litigation, initiates denaturalization cases, often after referrals from Homeland Security Investigations or other agencies. Immigration fraud cases, involving sham marriages, falsified asylum claims, or concealed criminal histories, also led to revocations. From 2004 to 2016, the government filed more than 300 denaturalization cases, compared with far fewer in prior decades. Case Study Four: Marriage Fraud and False IdentityNot all denaturalization cases involve war or terrorism. More ordinary fraud cases remind us that even seemingly small misrepresentations carry risks.