A survey of public attitudes to privacy has revealed NSW residents are worried about the transport Opal Card, which has reached 1.1 million users.

Half of the cards issued are able to track users' movements over 18 months, and are linked to bank accounts to allow for automatic top-up payments.

Privacy matters: The Opal Card can hold information about the movements of the card's owner and their bank account. Credit:Kate Geraghty

The NSW Privacy Commissioner Elizabeth Coombs is conducting the public survey as she reviews the operation of NSW privacy laws, which she fears are falling behind technological changes that have dramatically altered the privacy landscape.