Audio surveillance is increasingly being used on parts of urban mass transit systems. New Jersey Transit ended the program after revelations that it didn’t have policies governing storage and access to data from audio surveillance on some of its light-rail trains. ACLU-NJ deputy legal director welcomed the decision to end what she called, this extreme invasion of privacy” Baltimore Sun reported in March that the Maryland Transit Administration (MTA) has used audio recording systems since 2012. New Hampshire, Connecticut, Michigan, Ohio, Nevada, Oregon and California have either installed systems or moved to procure them.”]
Source: https://www.csoonline.com/article/3090502/big-brother-is-listening-as-well-as-watching.html