Is prayer unfalsifiable?

Some atheists say science has disproven the efficacy of prayer. Here's another atheist on whether the efficacy of prayer is scientifically falsifiable:

One problem with scientific testing of prayer is establishing that "nobody is praying over" the control.

 

You can ask people to pray for John, and to pray for Susan (to be healed from some disease), and if they pray out loud, you can observe them praying for John and Susan, but the fact that you did not ask anyone to pray for Jack does not show that no one prayed for Jack. How can you ensure that no one has prayed for Jack?

 

Suppose we determine that prayer always involves a specific brain-wave, and we also develop a mind-reading device, so that silent prayers can be monitored, and suppose we attach devices to every living human being on Earth so that when the prayer brain-wave is emitted, the mind-reading device kicks in and records the thoughts of the person who is praying. That would tell us whether someone had in fact prayed for Jack.

 

At least it would tell us whether someone who was living on this planet had prayed for Jack. But what about angels, spirits of the dead, and space aliens? Even if no human being had prayed for Jack, how can we know whether an angel, spirit, or space alien has prayed for Jack?

 

I suppose it is far-fetched to worry about angels, spirits, or space aliens messing up a prayer experiment, but if we are taking the God-hypothesis seriously, it is hard to see how we could simply assume that there are no angels, no spirits, and no space aliens who are concerned about the well-being of humans.

 

Furthermore, the prayer of an angel or a saint in heaven (a spirit) might well have greater efficacy than the prayer of some average churchgoer who participates in a prayer experiment. So, a single prayer by just one saint in heaven might do more for Jack than repeated prayers by a whole congregation of ordinary believers for Susan and John.

http://secularoutpost.infidels.org/2011/09/testing-supernatural-hypotheses.html?showComment=1315349343404#c7274782713805988593

It’s important to distinguish between verifiability and falsifiability. To say the efficacy of prayer is unfalsifiable doesn’t mean it’s unverifiable.