Drawing on Michel Callon’s classical study of scallop-farming, this chapter demonstrates the usefulness of the sociology of translation when it is applied to the problematisation of drug use in Europe. It argues for a shift in Actor-Network Theory-inspired thinking about politics – a shift from a concern with bad translation to good treason. The European Monitoring Centre for Drugs and Drug Addiction was set up as a decentralised European Union (EU) agency to provide this information, serving as an ‘obligatory passage point’ in the EU’s drug policy. The Portuguese drug policy, which is one of the most progressive within the EU, has been based on decriminalisation since the early 1990s, which means no one gets arrested for simply using drugs. The chapter shows how dominant ways of knowing are being challenged by social scientists, many of whom emphasise the importance of treating drug use as a social problem.