Nearly two decades after the devastating Bali bombing, terrorism still remains at the core of Indonesian national security. The government has programs on counterterrorism in order to eradicate terrorist attacks. A national auxiliary body,National Counter Terrorism Agency or Badan Nasional Penanggulangan Terorisme (herein after BNPT) has been established in 2010 with the main duty to eradicate terrorism in Indonesia with some strategic policies which consist of legal enforcement and anticipatory measures. However, terrorist attacks had occurred again in 2018 in Surabaya. This condition would have become worsened with the existence of digital media. By its nature, the Internet provides more opportunities for individuals to become radical since the Internet can give almost unlimited information including radicalism that nearly without filter from various sources. This paper is normative legal research with conceptual, historical, and statute approaches by which the result of this paper can be used as a reference for the government in eliminating digitalized radicalism in Indonesia. This paper argues that the Internet as one method of communication devices may become a very dangerous method of radicalization in Indonesia, in this case, self-radicalization because individuals may communicate and collaborate with terrorists and extremists who stay in other countries without physical contact. In this respect, radicalism would have spread easily and massive in Indonesia with the target of youth as the biggest user of digital social media. This paper analyzes de-radicalization programs by Indonesian government to stem the tide of radicalism that leads to terrorism including international cooperation in the Southeast Asian region as the ASEAN member states would like to build resilience against potential disruptive effects of digital revolution 4.0.