This article looks at human trafficking from a perspective influenced by the ‘vulnerability theory’ developed by Martha Fineman and her associates. It draws particularly on empirical studies of human trafficking from Albania to the UK and elsewhere. It suggests that Fineman’s approach needs to be modified to see the state not only as ameliorating vulnerability, or failing to do so, but as actively creating and using vulnerability to control or exploit its population. The fact that people are placed, for political, social and economic reasons, in situations of heightened vulnerability does not of itself deprive them of agency or responsibility. People should, however, be understood as ‘vulnerable subjects’ whose capacity for autonomy may be lost when they are deprived of supportive social relationships. The implications of this view for the criminal responsibility of trafficking victims are explored.