In response to the disinformation crisis, new policies, practices, and regulations will need corresponding practical technology solutions. This paper outlines five key functions that technology can serve: measure and track offline harms from online information, enable responsible algorithm design and review, label content, throttle the spread of harmful content, and track-and-trace online disinformation to its sources. Fortunately, many of the tools are available and in use. However, they need to be integrated into a holistic system that begins with recognizing disinformation and...