Abstract Within European law enforcement circles, counter-terrorism networks and privileged partnerships tend to be preferred to formal bureaucratic structures because of their flexibility and directness. The professional preference for informal, bilateral and privileged relationships may, however, undermine the potential of formally established agencies such as Europol and Eurojust, which work through national and centrally co-ordinated channels of information and intelligence. This article seeks to assess whether standards of democratic, legal and social legitimacy are under pressure as a consequence of this persistent preference for horizontal, direct and informal co-operation.