In 2020, for the first time, millions of U.S. residents can respond online to the census, hundreds of thousands of federal workers will use handheld devices to conduct the decennial count, and news about the census will travel through social media channels in real time. Our nation’s first “digital” census presents myriad opportunities for a truly participatory count, but a number of issues—some old and some new—may create obstacles toward a complete and accurate count.