Nigeria’s Economic and Financial Crimes Commission (EFCC) has uncovered a massive online fraud operation, arresting 792 people—including foreign nationals—accused of running cryptocurrency and romance scams. The arrests were made on December 10 in Lagos, Nigeria’s commercial hub, at a building known as "Big Leaf," where the scammers were allegedly operating.

The suspects include 148 Chinese nationals, 40 Filipinos, two individuals from Kazakhstan, one Pakistani, and one Indonesian. Accor...