Especially in the aftermath of 9/11, states’ counterterrorism efforts have increasingly sought to use criminal law preventively, by criminalizing conduct before a terrorist crime is committed, including preparatory acts, and acts that contribute or support terrorism such as financing or providing material support. While a preventive use of criminal law is not in itself problematic, basic principles of human rights law pose limits to its use. In this context, the current Chapter analyses recent legislative-type counterterrorist resolutions by the Security Council in the areas of criminalising "foreign terrorist fighters" and the financing of terrorism. It argues that in both Resolution 2178 (2014) and Resolution 2462 (2019) the Security Council has also increasingly moved towards the criminalization of conduct before a terrorist crime is committed. Such a move poses dangers not only for a number of international legal standards, but also for humanitarian workers operating in certain contexts, while a number of questions remain with regard to the application of these legal regimes and how they interact with the existent counter-terrorism architecture, in particular the proscription of terrorist organizations at the national level and the Security Council ISIL (Da'esh) & Al-Qaida Sanctions regime, as well as the work of the Financial Action Task Force (FATF).