In the wake of the recent hostage crisis, which was largely played out on the Internet, every section of Japanese society must work together to prevent extremism taking hold in the country's online social spaces, an expert on digital hate speech and terrorism said Monday.

Rabbi Abraham Cooper, associate dean at the Simon Wiesenthal Center, a U.S.-based Jewish human rights organization, told a news conference in Tokyo that Japan is just as vulnerable as Western countries to the risk of terrorist groups using social networks to recruit fighters and provoke them to carry out lone wolf attacks.

Cooper, who has headed a task force on digital hate speech for 20 years, said the Islamic State militant group's manipulation of social networking heralds a "new era" of terrorism, where instructions for making bombs and other weapons are delivered to would-be attackers in slick online magazines in multiple languages.