Micro(phones) is the word of the day. From The Grey House, Book One:
Vincent watched as the mysterious woman led Anthony away. From his security office, he could see the whole club. He followed them as they walked from one screen to another. His blood boiled as she took the bait. There was one section of the private room that was set up to be out of the way. There were hidden cameras everywhere, but only that corner had microphones.