Too central to fail?
Network analysis of 12 global financial institutions that received the most emergency loans from the Fed during the financial crisis. Battiston et al. (2012) develop a measure of systemic risk called "DebtRank" that reflects how vulnerable the entire banking system is to each bank's fragility. They find that even banks that took only a moderate amount of loans (lighter shades of blue) could be systematically important if they were sufficiently connected to other banks.
 
Source: Figures 7-11 in supplementary information for Battiston et al. (2012)