Smart TVs have rapidly become the most common smart appliance in typical households. In the U.S., most television sets on the market have advanced sensors not traditionally found on conventional TVs, such as a microphone for voice commands or a camera for photo or video input. These new sensors enable features that are convenient, but they may also introduce new privacy implications. We surveyed 591 U.S. Internet users about their current understanding and expectations about how smart TVs collect and use data. We found a wide range of assumptions and opinions among our respondents, and a good deal of uncertainty about what’s collected and how it is used. In addition, these assumptions and opinions varied between data types and sensors. One area where we found broad agreement was that it is unacceptable for the data to be repurposed or shared. But there was little understanding of the protections—or lack thereof—afforded by current laws and regulations to constrain such sharing. We hope that our findings will enhance end-user privacy by providing useful insights for smart TV manufacturers, regulators and lawmakers, and designers of privacy-enhancing technologies.