[1] Travel and customer information for NSW travelers can be accessed by police, as confirmed by the New South Wales Department of Transport.
[2] The information is gotten from the Opal smart card ticketing system, which started working in 2013.
[3] The government will stop the use of some of the multi-trip cards, including periodic tickets to push travelers to switch to the Opal card.
[Source] http://www.zdnet.com/au/sydney-opal-card-travel-history-can-be-accessed-by-police-7000031048/