From Bearing Arms:

On July 26, the New Zealand Herald reported that the country’s new Firearms Safety Authority had compromised the personal information of more than 100 gun owners. The paper explained,

In an email sent shortly after noon on Wednesday, seen by the Herald, Auckland Central Police District firearms staff emailed more than 100 gun owners to warn them their listed firearms licence address may not be up to date.

Their email addresses, in many cases including their first and last names, were visible in the cc field, rather than hidden in the bcc section.