The City of Hamilton has notified hundreds of voters who requested a mail-in ballot that some of their information was exposed in a privacy breach.

The city clerk says the breach happened in an email the city sent Thursday providing information to approximately 450 voters who registered for a mail-in ballot.

Photos of the email show multiple email addresses entered into the “send” line of the message, instead of under “bcc”, which exposed the email addresses to everyone who received it.

The city says it took immediate steps to recall the message, but it remains in some voters’ inboxes.

The city clerk is asking everyone to delete the email.

“We regret any distress that this incident may cause those who have used the Vote by Mail process,” City Clerk Andrea Holland said in an email obtained by CHCH News.

“We take these matters seriously and will be taking steps to review our processes to ensure staff are trained in the protection of personal information.”

Oh dear, got a “Vote By Mail Update Municipal Election” email to those who requested mail-in ballots (followed by two “recall” emails) and they cc’d us all!!! How is that right for privacy… 🤦🏻‍♀️ #HamOnt

— Kristin (@kristin_archer) October 13, 2022

Affected voters can file a privacy complaint online with the Information and Privacy Commissioner of Ontario. Anyone who is now unable to return their mail-in ballot on time can file a complaint with the Ontario Ombudsman.

The city says nearly 3,500 voters are registered to receive online ballots for the upcoming municipal election.

Ballots had to be mailed by Canada Post by Thursday, but they can still be dropped off at a municipal service centre until Oct. 21 or at City Hall by election day on Oct. 24.

READ MORE: Over 2000 privacy breaches at St. Joseph’s Healthcare Hamilton since 2018