COVID-19 contact tracing applications have been deployed at a fast pace around the world and may be a key policy instrument to contain future waves in Canada. This study aims to explain public opinion toward cell phone contact tracing using a survey experiment conducted with a representative sample of Canadian respondents. We build upon an established theory in evolutionary psychology—disease avoidance—to predict how media coverage of the pandemic affects public support for containment measures. We report three key findings. First, exposure to a news item that shows people ignoring social distancing rules causes an increase in support for cell phone contact tracing. Second, pre-treatment covariates such as anxiety and a belief that other people are not following the rules rank among the strongest predictors of support for COVID-19 apps. And third, while a majority of respondents approve the reliance on cell phone contact tracing, many of them hold ambivalent thoughts about the technology. Our analysis of answers to an open-ended question on the topic suggests that concerns for rights and freedoms remain a salient preoccupation.