This paper assesses the potential implications of the ECtHR’s positive duties to mobilise the criminal law on domestic criminal justice systems. It shows that the Court tends to present criminal accountability as indispensable to protect human rights. This approach may foster a ‘culture of conviction’ at the domestic level whereby punishment is seen as the end to pursue whatever the cost. While the jurisprudence currently refers to the duty to punish as an obligation of means, increased concern with the efficiency of the criminal system in preventing crime is leading the Court to consider whether adequate punishment has been imposed. Such uncritical invocation of conviction and punishment might in practice encourage limitations to due process rights, harsher punishments and wider powers of arrest and detention. Conversely, criminal justice reform initiatives, directed at reducing unnecessary criminalisation and implementing alternatives to prison, are totally neglected.