Voice logging is the practice of regularly recording telephone conversations. Business sectors which often do voice logging include public safety (e.g. 9-1-1 and emergency response systems), customer service call centers (conversations are recorded for quality assurance purposes), and finance (e.g. telephone-initiated stock trades are recorded for compliance purposes). Although voice logging is usually performed on conventional telephone lines, it is also frequently used for recording open microphones (e.g. on a stock trading floor) and for broadcast radio.