I read the link and rejected its pages of persecution-complex thesis and lack of worthwhile supporting evidence. The grand jury compels activists to testify wh

I read the link and rejected its pages of persecution-complex thesis and lack of worthwhile supporting evidence. The grand jury compels activists to testify when they are involved with or witness to crimes and conspiracies. The witnesses are not picked at random or for political purposes, but some political groups that have violent edges will sometimes find themselves facing a society that does not share its appreciation of "direct action". Some of the more radical elements of the groups you mention _are_ criminal and dealing with the via criminal prosecution is much better than the alternatives (which is not to just leave them alone but rather to treat them as terrorists, traitors, unlawful combatants, or simply line them up against a wall and shoot them.)