Can a subpoena be used to obtain personal information of a grand jury panel member?

Here the subpoenas and questionnaires addressed to the grand jury panel would elicit personal information to facilitate an indicted defendant's complaint of grand jury selection procedures. The vulnerability of grand jurors and panel members to this kind of inquiry without a counterbalancing inquiry into the defendant's actual or potential prejudice opens the door to delaying tactics in criminal cases and discourages Californians from undertaking grand jury service. (Cf. City of Carmel-By-The-Sea v. Young (1970) 2 Cal.3d 259, 270, 85 Cal.Rptr. 1, 466 P.2d 225.) The problem becomes more pointed because, according to the record, grand jurors in Nevada County spend 95 percent of their time investigating local governmental affairs, only five percent of their time of the criminal phase of their work. Thus, at the cost of pretrial delay in a felony prosecution, we issued an order to show cause.