You bring up a good point, sir.
As you know, there is no mechanism right now to compel the attendance of a witness with respect to a terrorism investigation. Of course, the investigative hearing could be utilized to compel a witness with respect to a terrorist act about to be committed.
But it does come down to a strategic decision at the time of the investigation, so we would have to assess, first of all.... Let's say that it was not an imminent threat, but there was information to be gleaned with respect to the investigative hearing, or there was information to be gleaned from a witness regarding either a past terrorist attack or one that's about to occur. We would have to assess whether taking that approach would put the investigation at risk.
Many factors have to be taken into account, of course. If we have sources involved and if there are police agents and wiretaps, we have to take into account the safety of those people. There are many factors that come into play. So we would look on a case-by-case basis at whether we would go towards an investigative hearing for a witness or for a person of interest at that point.