Not the Vong interdictors. In two if the NJO books (the second stackpole one and the first edge of victory one) the interdictors actually create a gravity well. In one, they ues it to force a Vong cruiser to shunt all its dovin basals into its drive, so that it will not be pulled into a moon of Ithor. By forcing it to direct its dovin basals into propulsion, they can't be used for shielding.
In the other, an interdictor is used to disrupt a system's lagrange points so that a NR fleet can jump into the system in an area that the Vong haven't picketed. It's like this: a jump node is surrounded by mjolonirs, and you have to get into the system. What do you do? Disrupt the gravitic balance of the system by sending an interdictor through the node so that the node moves to a different spot, away from the Mjolonirs, just long enough to get a fleet into the system. Of course, the sentries will kill the cruiser, but it is better to lose one cruiser than an entire fleet.
[This message has been edited by ^Graff (edited 12-10-2001).]