....non-cooperation with a grand jury is possible but carries great risk. Despite the fact that witnesses are offered immunity from criminal prosecution — and thus self-indictment — if they refuse to talk they can be held in federal custody for 18 months or more for contempt. Two anarchists in the Pacific Northwest on Friday were released from federal detention having refused to talk to a grand jury when subpoenaed — they had been imprisoned for five months for their silence, kept for long periods in solitary confinement. For Norton, the mother of a 7-year-old girl, the risk loomed large.