The Interdictors themselves are often very vulnerable to enemy fire
Interdiction: Interdiction in EVE refers to the use of specific Interdictor-class ships, tech 2 destroyers capable of using the special RuneScape Gold "Interdiction Sphere Launcher".
These launchers launch a temporary warp inhibition field that stops all ships within it from warping - no matter what their warp core strength or ship class. If within a field, the only option is to either accelerate out of the field or destroy the field itself.
The Interdictors themselves are often very vulnerable to enemy fire, as they have lackluster passive defenses, sporting the signature of a small cruiser and the tanking abilities of a frigate, with their speed falling somewhere in between.
This fact has led them to be nicknamed "Flying Coffins" by some players, but their tactical use often outweighs the risk to the pilot. Many feel that the loss of a twenty-odd million ISK ship can be an acceptable loss compared to nailing down an entire enemy fleet.
As a result of their weakness and tactical importance, Interdictors are very much advanced ships, requiring some skill on the part of the player (not to mention the in-game skill requirements of flying these require at least three weeks of training or so).
The Interdiction Sphere's dynamic nature and short duration makes it ideal for larger scale fleet engagements as well as smaller hunting parties, but less useful for stationary camps.