They are already on the US terrorist list. The pitiful Japanese government tried to apply the so-called strengthened "haboho" or "sedition laws", but their liberal courts threw it out several years back. All residents can do is observe them from a distance, take notes, and try to chase them out from apartment complex to apartment complex.
Accordingly, except for the top tier of the leadership from the sarin gas attack days that are/were in prison, a new generation and level of leaders took their place. All under the eyes of the Japanese LEOs.
Well, Dr. Frank-san, we will sadly be hearing more from this group, Aleph (Aum Shinrikyo) IMHO, but because it has to do with Japan, not many people in the United States or West will have interest until something dramatic and serious, unfortunately, has happened.
They already scoped out Disneyland in California as well as US military bases in Japan as potential sites for their attacks, but were thwarted. They have financial power, technical (computer, telecom, biological, chemical) prowess, international savvy and reach, and a total armageddon world viewpoint that dicatates it is their manifest destiny to destroy everything.