This paper discusses the process of radicalization in cyberspace. It will look at how and why Indonesia are vulnerable in society and targeted by terrorist organizations in an attempt to recruit them, especially in cyberspace. The terrorists have become expert, not only using the latest tools of internet communications, but to do it in a way that can shield their identities and even their locations when spreading the radical ideology. The concept that used in this paper is cyber-radicalization, which is the new concept that merged from cyber threat and radicalization. The result from this paper shown that Indonesia netizens (internet users) had great potency to fight radicalization in the cyberspace and thecapacity for supporting government counter-cyber radicalization agenda. However, fighting cyber radicalization in that way faced several challenges. Therefore Indonesia’s government should benefited the netizens to reach the optimum point on counter-cyber radicalization agenda.