The manufacture, sale, installation, and monitoring of these devices is a multi-billion dollar industry in North America. Unless you are a law enforcement agency with an Order or Warrant for a wire tap, it is a criminal offence to record the conversations of two or more persons without their consent. Confidential information seems to be getting out to competitors.
Competitors seem to be just one step ahead all of the time.
Your office was broken into yet very little or nothing was taken. Vehicles parked near to your premises, that appear to be empty. Your telephone rings but no one speaks or you just hear a short tone. Repairers or utility companies turn up to carry out work when they have not been called. Furniture or items appear to have been disturbed.