It may already be going on. I would almost be surprised if it were not. I am referring to Big Brother and or any other third parties having placed active spy/hearing (and even camera/video) devices into at least some confessionals.
It would almost seem like a win-win situation for the "prince of this world" (aka: the lord of the flies and father of lies). Win #1 -- people are not aware of the potential for spy device and thus don't pray for protection. Win #2 -- people are aware and shy away from the confessional IF because of the potential for spying they end up being too afraid to confess.
We may one day face a world -- at least a TradCat world -- where debugging/detection devices are provided to priests as a standard precaution for running or maintaining an ongoing counter "scan" of the "box."
In any event, I would think it an excellent idea to say a prayer to our guardian angel, St. Michael the Archangel, or even to God Himself to protect our communications from any snooping device in whatever way is best.
Not to scare anyone, but I'm afraid we are already inundated with surveilance monitoring -- as if you didn't already know!
Here are just 3 snippets of our "brave new world."
http://www.advanced-intelligence.com/infinity.html#!au046https://spyassociates.com/listening-deviceshttp://www.ebay.com/bhp/listening-devices-bugs