This paper is concerned with the changes occurring into what has been called the field of European Union (EU) internal security (Anderson, den Boer 1994; Bigo 1996; Sheptycki 1998). The notion of field is used to avoid that a vision of the multiple different practices of the actors who gather and compete to define security and insecurity, being reduced to a discussion on the progress or not of the institutions of the EU and an analysis of the success or failure of a spill over in matters of sovereignty. The existence of an EU internal security domain called Justice and Home affairs is not an autonomous domain that security studies can isolate as an object as such (Kees Gronendijk in this volume). The question of EU internal security is derivative from the practices of freedom of movement in the EU, of who is entitled to cross borders, to stay, to work to live with his family. This area, or better this social space is constructed as a field because many social actors who do policing, border controls, migration management, reception of refugees have been interested and pushed into strong disputes around the idea of an European internal security and have fought to privilege their reasoning and tools over the others, in order also to guarantee their funds and missions. The socio-genesis of the field of EU internal security is correlated with the transformations of practices of freedom for people to move and the ways this management of their travel has been correlated with the traditional tasks of coercion in case of crime and violence that police do, as well as the way they treat their citizen and the foreigners in these cases. The field is therefore a field of power, where different professionals engage transnationally on the best and worst practices that the other national traditions consider as legitimate options for coercing individuals in a specific state. Far from opposing homogeneous cultural entities of nations represented by their governments and their representative (commissioners, and permanent representation), a study of the last forty years shows that the alliance and the fights follow often about the way actors do their job, the similarity or not of their routines, their habitus and trajectories (Adler-Nissen 2012; Kauppi and Madsen 2013). To be a policeman, a gendarme, a border guard, whatever the country, is more important than the nationality, and frames how people act, beyond the diplomatic negotiation done in Brussels. This is what I have called transnational guilds (Bigo 2016). They are structured by the specific skills necessary to do a job, and the form of recognition about who is an expert on this domain, sometimes not in accordance with the formal hierarchies at work into institutions. As it has been explained many times such a research imposes combining different disciplines, which have all their own 401narratives about the history of EU internal security (Bossong and Rhinard 2016). Many books have described what they call the emergence of the third pillar of the EU and the development of an area of freedom, security, and justice, where the key word is security and policing. These authors provide a detailed understanding of the juridification of sectors of national policing under the construction of the institutions of the EU and the tensions it has created. They are Europeanists political scientists and sometimes lawyers. They begin their books with the Maastricht Treaty and they look at the legal effects of the Europeanisation of policing in terms of criminal justice and border controls. This first line of thought is important by its detailed knowledge on policy making and its description of the personnel of the EU institutions as well as the impact of the norms of policing (Den Boer and Walker 1993, 2011, 2013; Mitsilegas, Monar and Rees 2003; Monar 2002, 2013; Wallace Hélène &Wallace William 2000) but this Europeanist narrative does not give the same picture than the one produced by the sociologist of policing and the criminologists. The latter insist more on the dynamics of the national polices, their models of policing, the dynamics that have constituted national polices from the eighteenth century and the Europeanisation from the nineteenth century giving to the field of policing a different historical scale (Anderson Malcolm, den Boer Monica 1994; Deflem, 2000; Liang, 1992). They insist on the longue durée of informal clubs of policemen, on the transatlantic links which have framed the field and which continue to be central nowadays to understand how policing in its management of violence (counter subversion, counter terrorism) is more and more connected with border controls and surveillance (Bigo 2014; Carrera and Mitsilegas 2017; Collantes and Celaldor 2012; Guild and Carrera 2013). The third approach which is necessary to have in mind to understand EU internal security is the social use of technologies by different actors, the correlations between technologies, surveillance, tracing of mobilities, identification of people, anticipation of behaviours. Based on sociology of technology, digital and surveillance studies as well as critical legal studies, this third line of thought connects researches on surveillance and human rights affected by transnational dynamics of control of mobility (and not only at borders). It includes a reflection on the objects by which security is produced and by an interest on the targets or unexpected victims, these competitions between actors produce (Brouwer 2008; Guild 2006; Mitsilegas 2008). The last image is more complex and diffracted than the other ones. Its advantage is sometimes to ask new questions about what seems pure technicalities: the passports, the visas, the databases, and the people who construct them and ‘support’ the non-specialists on technologies. This is also a way to understand some key transformations at stake in the general economy of the field of internal security today in its relation with the EU institutions and in the incremental use of digital technologies to regulate the circulation of people and the reframing of what is security in terms of preventive policing.