Philosophical questions surround trolls, but these two Drupal modules strike me as the fundamentally wrong approach: Caving trolls creates echo chambers (see slashdot and dailykos*) and misery crosses ethical boundaries.

* Neither slashdot or dailykos use Drupal or cave, but both implement the same strategy of hiding posts that disagree with the dominant ideology. A little time in their comments will show why that is a horrible approach.