The data collection system used by Auckland Transport's new electronic Hop card could soon be rolled out around the country, despite concerns about card users' privacy.
When the $100 million Hop card system was introduced, Auckland Transport said it reserved the right to share users' personal information with third parties, including business partners offering products and services.
Commuters registering a new Hop card are required to provide their name, email address, phone number and birth date.
Civil libertarian Thomas Beagle said on Friday the possibility of such a system going nationwide should worry anyone concerned about maintaining their privacy.
Councils around the country have either committed initial funding to the project or are deciding whether to join the system.