Approximately 4,500 customers who purchased marijuana from Ontario’s online cannabis store have had some of their personal information improperly accessed, the latest setback for the rollout of legal pot in Canada’s most populous province.

A spokesperson for the Ontario Cannabis Store said the organization learned on Nov. 1 that some of its customers’ shipping data was accessed by an OCS customer through a Canada Post website vulnerability. That individual was able to obtain limited access to the names and addresses of OCS customers as well as their postal codes, the name of the person who signed for the package and the OCS’s corporate name and business address.

“The OCS has worked closely with Canada Post to identify the cause of this issue and to prevent any further unauthorized access to customer delivery information,” the spokesman said in a statement posted on the company’s blog.

Jon Hamilton, a spokesperson for Canada Post, said the country’s postal service has been working with the OCS since it discovered the privacy breach and that “important fixes have been put in place by both organizations to prevent any further unauthorized access to customer information.”

“We have also shared with OCS that we are confident that the customer who accessed the information only shared it with Canada Post and deleted it without distributing further,” Hamilton said in a statement to BNN Bloomberg.

Both the Federal Privacy Commissioner and the Ontario Information and Privacy Commissioner have been notified about the data breach, Hamilton added.

A spokesperson for Ontario Finance Minister Vic Fedeli didn’t immediately return BNN Bloomberg’s request for comment on the breach.

The privacy violation is the latest stumble in Ontario’s short history handling legal recreational cannabis since last month. Customers have made more than 1,000 complaints to the provincial ombudsman about billing problems, poor customer service and mislabelled items from Health Canada-authorized licensed producers that led to significant delays.

The OCS is the only source of legal recreational marijuana in the province until private sector retailers can open their doors in April. Canada Post is the main shipper responsible for delivering cannabis throughout the province, although Purolator is also tasked with shipping legal pot.

In a background meeting ahead of the launch of legal cannabis in Canada, OCS officials stated that the online retailer will minimize the amount of customer data collected and store all data in Canada for the minimum length of time required by law before it is deleted. As well, visitors to the site will not be required to create an online account or profile, OCS officials said.

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