Images of Penguin Group's facilities in the town of Hernandarias, two kilometers from the colossal Itaipu dam on the Parana River in Paraguay. The company's hundreds of computers are lined up on a large field the size of a football field to provide cloud storage and data processing services. Paraguay is attracting dozens of legitimate cryptocurrency companies looking to turn the South American country into a "tech hub," but its giant dams and cheap energy are also attracting outlaws who are mining digital currencies illegally and on a large scale in a context of endemic corruption. STOCKSHOTS