Following the recommendations of the 9/11 Commission, the Department of Homeland Security (DHS) and the states cooperated in the establishment of fusion centers to facilitate sharing of data across government agencies, as well as across the public and private sectors. Based on interviews with officials in thirty-six different fusion centers and review of government documents and reports on fusion centers' activities, this article analyzes the interjurisdictional, regulatory, and legal accountability arrangements for these centers. Our findings indicate that fusion centers operate in a manner consistent with ''opportunistic federalism'' or ''soft governance.'' Accountability in such a setting is particularly difficult but especially in the absence of shared professional goals as appears to be the case for fusion centers. The Department of Homeland Security (DHS), under both the Bush and Obama administrations, has supported the creation of ''fusion centers'' with a mandate to share data across government agencies as well as across the public and private sectors. The stated goal of fusion centers is to ''blend relevant law enforcement and intelligence information analysis and coordinate security measures to reduce threats in their communities'' (U.S. DHS 2006). Concerns about privacy and surveillance, as well as about effectiveness and accountability, have surfaced in response to these centers. As of August 2013, there were seventy-eight DHS primary and recognized 1 state and local fusion centers. Some of these were created in response to terrorism concerns, whereas others emerged from existing law enforcement organizations, such as drug interdiction, crime control, or regional coordination. This article analyzes the interjurisdictional, regulatory, and legal accountability arrangements for these centers. With their goals of information sharing, ''connecting the dots,'' and moving beyond traditional information silos, fusion centers operate across a variety of jurisdictional boundaries, which often exist in different regulatory and legal environments. It is generally challenging to design and manage accountability in such multijurisdictional and multipurpose settings. A lack of clarity about the organizational position, and hence the accountability, of