Funny you should bring this up. I suspect there might be something very interfering in this type of technology with respect to prayer between man and God. It's also one of the few things that might mark a turning point in what God will simply allow to ensue unanswered. I believe it's treading on thin ice, spiritually.
This technology is no more complicated than a mood ring. It leaves no marks on the body. All it does is measure brain activity. Reading actual thoughts is not even possible yet.
It will psyche those nuts out. If it scares us, imagine how much it scares them.