It's a Dominionist tactic, I believe. I think it's pretty much against Christ's teachings---he did say that if one you preached to did not receive your word, that you should just shake the dirt from your sandals and leave to find more receptive listeners. The goal was for man and God to be joined via Christ, no? And it was important enough to leave if all you were getting was an argument. Time's a-wasting.
This guy doesn't have that goal, I don't believe. His goal seems to be, how do I get people to pay attention to me? Aha! Ask for "imprecatory prayer". Something I've never heard of. Isn't that just sort of a tarted-up version of asking God to damn someone? There are so many needy people---they could use love, a hug, a warm dinner...this guy could really fill a need. Instead, he does this. It's a shame.