Surveillance began with counting the numbers of people in the population. At various times in history, numbers have been used to assess the overall strength of the population, to identify the march of dangerous contagion, or to determine needs for food or labor. But even simple counting of population numbers, vital statistics, or reports of disease has been controversial. Information is power and the most rudimentary surveillance can be used both for good and for harm. This chapter sets ethical questions about these basic surveillance methods in historical and epistemological context. It gives examples of uses of data about population numbers, vital statistics, or outbreaks that have been clearly beneficial, as well as examples that have bordered on the genocidal. Counting numbers, as a rudimentary epidemiological method, also presents the opportunity to explore ethical problems raised by epidemiology as a science, such as incomplete data, biased data, or false negatives or positives. Today, with increasing understanding of disease and availability of prevention or treatment, the advantages of outbreak detection may be shared far more widely and more equally. Nonetheless, outbreak detection can generate fear and hostility if patterns of disease track otherwise disfavored groups. COVID-19 has revealed the importance of demographic data about the distribution of disease burdens—data that may either generate mistrust as people see their disadvantage starkly, or that may foster trust if the result is increased attention to disparities in treatment and in health.