YES, I realize this song is about the pre-SHTF troubles in Northern Ireland (interesting that we now think of that horrible time as less than completely catastrophic). And, NO, I do not think of this song as being about the undead. It still strikes the chord which the author, Dolores O'Riordan, intended: those who have died in the violence of the outbreak, of whatever cause, haunt us, drive us insane. We must be careful not to lose sight of the fact that survival is not the ends, but the means to create a new life. If we are consumed by the violence that was necessary during the outbreak, we not only decrease our chances for survival, but also make it less likely that the new world will be worthwhile.
Oh, and it has a great, driving beat.