When Anne received an urgent email from an apparent Federal Trade Commission agent alleging there was a demand for payment and a warrant out for her arrest over fraudulent purchases, she nervously shared her phone number with the sender. The 77-year-old followed instructions she received by text message to pay $9,000 in cash into an ATM at a gas station near her home in Chicago. But the machine where she placed her money wasn't a normal ATM connected to a bank — instead, it was what’s known as...