Anyone else think this should be one per turn? I have yet to be hit by it, but when building corp decks its definitely a card I always consider. I play NBN and have now won a couple of times finishing their cheap 2 cost Agenda that provides a one turn, two-tag situation and then playing Scorched Earth. As I've gotten more core sets, I see how to make two Scorched Earths in one turn a pretty consistent possibility. Just seems cheesy to me.
Then again, furture expansions will undoubtedly have better meat damage reduction cards that have secondary effects and make them not so worthless. So, the situation will probably work itself out.