From the FTC:
The Federal Trade Commission (FTC or Commission) is an independent U.S. law enforcement agency charged with protecting consumers and enhancing competition across broad sectors of the economy. The FTC’s primary legal authority comes from the Federal Trade Commission Act, which prohibits unfair or deceptive practices in the marketplace. The FTC also has authority to enforce a variety of sector specific laws, including the Truth in Lending Act, the CAN-SPAM Act, the Children’s Online Privacy Protection Act, the Equal Credit Opportunity Act, the Fair Credit Reporting Act, the Fair Debt Collection Practices Act, and the Telemarketing and Consumer Fraud and Abuse Prevention Act. This broad authority allows the Commission to address a wide array of practices affecting consumers, including those that emerge with the development of new technologies and business models.
Read their annual report, which provides examples of different types of cases, on their site (pdf).