%0 Conference Paper %B MAIN Workshop at AAMAS 2013 %D 2013 %T Bayesian Security Games for Controlling Contagion %A Tsai, Jason %A Qian, Yundi %A Vorobeychik, Yevgeniy %A Kiekintveld, Christopher %A Milnd Tambe %X Influence blocking games have been used to model adversarial domains with a social component, such as counterinsurgency. In these games, a mitigator attempts to minimize the efforts of an influencer to spread his agenda across a social network which is modeled as a graph. Previous work has assumed that the influence graph structure is known with certainty by both players. However, in reality, there is often significant information asymmetry between the mitigator and the influencer. We introduce a model of this information asymmetry as a two-player zero-sum Bayesian game. Nearly all past work in influence maximization and social network analysis suggests that graph structure is fundamental in strategy generation, leading to an expectation that solving the Bayesian game exactly would be vastly superior to any technique that does not account for uncertainty about the network structure. Surprisingly, we show through extensive experimentation on synthetic and real-world social networks that many common forms of uncertainty can be addressed near-optimally by ignoring the vast majority of it and simply solving an abstracted game with a few randomly chosen types. This suggests that optimal strategies of games that do not model the full range of uncertainty in influence blocking games are in many cases robust to uncertainty about the structure of the influence graph. %B MAIN Workshop at AAMAS 2013 %7 2 %V 27 %P 200-217 %G eng