In Allmaras et al. [Inverse Prob. Imaging, Vol. 7, No. 1, p. 47 (2013)], we present the mathematical foundations for the passive detection of small low-emission radioactive sources buried in background noise using Compton gamma cameras. Here, we apply these techniques to the detection of small amounts of special nuclear material in various cargo container geometries. Simulated two-dimensional data are used. We demonstrate the feasibility of such an approach using various realistic cargo container loadings and assess the effect of angular detection errors in Compton cameras.