Attacks on health workers, clinics, hospitals, ambulances and patients during periods of armed conflict or civil disturbance pose enormous challenges to humanitarian response and constitute affronts to the imperatives of human rights and civilian protection. Violence inflicted on humanitarian aid workers is gaining the global attention it warrants. While the number of attacks on aid workers has decreased in recent years, in a handful of places, notably Sudan, Afghanistan, and Somalia, they have become more spectacular and frightening, with aid agencies targeted for kidnapping and subjected to use of explosives because of their perceived affiliation with Western governments. The assaults have galvanised the humanitarian aid community to track attacks and to engage in intensive and sophisticated discussion of means to increase operational security. After worldwide consultation, in 2011 the United Nations (UN) Office for the Coordination of Humanitarian Affairs (OCHA) issued a report that summarised the fruits of experience and stimulated consideration of security strategies for aid providers. By contrast, however, until very recently the far larger number of incidents of violence inflicted on and interference with indigenous health services and on international and local development agencies by state and armed groups has received comparatively little attention.