I'm sure with Hawaii's extremely high standards of government competence that there could never be a breach (the California Department of Justice terms it a "security incident") of the firearms registration information, permits to acquire, RapBack data, CCW applications, etc.
The more likely scenario here is that such a "security incident" wouldn't even be discovered, and if it was it wouldn't be revealed to the public, because, like the answer I've received on several occasions, that's "attorney-client privileged information". (i'll just mention here, again, the unsubstantiated rumor that such information was "leaked" by "an insider" to facilitate firearm thefts by burglars. Again, "unsubstantiated rumor". That could never happen here in Hawaii right? An employee of the Police Department stealing information to facilitate crimes? I'm sure there are multiple layers of rigorous security in place to prevent that from happening.

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California DOJ Security Breach Releases Gun Owners’ Private Informationhttp://kogo.iheart.com/onair/the-demaio-report-56776/california-doj-security-breach-releases-gun-15443140/(includes a 5 minute interview with the woman firearms trainer who received notification that her personal information was revealed).
Excerpt:
Who needs Russian hackers when you have politically-motivated bureaucrats at the California Department of Justice?
The identity and personal information of thousands of California gun owners was “inadvertently” released under a bungled records disclosure by the DOJ. Name, home address, drivers license, and a variety of other confidential and private information was released.
Worse, the incident occurred in mid October of 2016 but the victims of the identity breach were not notified until the last few days of December. The letter below has been sent from the DOJ and is now landing in the victim’s mail boxes.
Gun owners are already nervous about registry requirements being misused by government to target gun owners. The inadvertent release now gives gun owners even more reason to be worried.