The SLA never had more than a dozen members, and has not existed for half a century. To put that into reference, Hearst was 19 when kidnapped, and is 72 now.
How do we know there are not other organizations like the SLA? They were never a quiet group. If there were "many thousands" of domestic terrorists attacking us, we would notice.
The reality is that California schools are doing the research that is providing the breakthroughs of today, and tomorrow. You cannot brainwash people into making breakthroughs in research.