Digital Platforms are becoming essential building blocks of modern economies, facilitating an unprecedented scale of economic transactions and activities. At the same time, an increasing number of laws and regulations are drafted, discussed, and ready to reshape the landscape of digital platforms. This course is an introduction to the economic scholarship on various legal and regulatory problems faced by digital platforms. It covers a variety of contentious topics, such as digital copyright, intermediary liability, content moderation, censorship, privacy, cybercrimes, etc. Despite the digital context, many policy questions discussed are also common in the economic analysis of law and such connections will be emphasized throughout the course. The course will be particularly helpful to students interested in either understanding the digital economy or applying economic reasoning to legal problems.