To increase resiliency, it would probably be prudent to assume worse-case scenarios. Best to assume that if a court order is sent to a witness, it orders them to not disclose the order to anyone and not to do anything that interferes with the order (i.e. can't pull a deadman's switch, can't shut down their node).
Also, even better to assume an international coordinated action by police/courts/governments/etc., aimed at changing the Hive network or gaining control over it. Better to assume the police is involved and they find out who the people running the witness nodes are, and can physically reach their homes. What then, if they reach the top 17 or top 20 and can threaten and silence them?