Medical-marijuana patients in Canada who say the government breached their privacy are taking their complaints to a Federal Court judge in Halifax, Nova Scotia. Attorneys for the two lead plaintiffs, who have been identified only by pseudonyms, will propose in June a class-action lawsuit on behalf of the country’s 40,000 medical pot users who received Health Canada mailings that named the marijuana program on the front of the envelopes alongside the recipients’ names, according to the Chronicle Herald in Halifax.

Sent in November 2013, the mailings were delivered to participants in Canada’s government-run medical-marijuana program -- patients who have been approved to use marijuana for medical purposes -- as well as licensed cannabis growers. Many criticized the mailings as careless and said they exposed patients’ private medical information. To add insult to injury, some of the envelopes meant for program participants were accidentally delivered to neighbors’ homes.

Before the 2013 mailings, all correspondence between Health Canada, the agency in charge of the country’s national health-care system, and participants in the program were sent in plain envelopes that did not include the program’s name or any reference to marijuana on their exteriors. Health Canada acknowledged that including the name of the program on the envelopes was a mistake.

“As soon as it was discovered, my phone started ringing off the hook with individuals who were very upset,” David Fraser, a lawyer with the Halifax firm McInnes Cooper, told the Chronicle Herald Wednesday. “This exposed their name and their connection with the Marijuana Medical Access Program ... We’ve heard a number of cases where the individual piece of mail was misdirected and went to the neighbor’s house. This is very sensitive, private information.” McInnes Cooper is one of four law firms handling the case.

Canada paved the way for medical marijuana in 2000 after a court overturned a law barring patients from accessing marijuana. However, the drug remains illegal in the eyes of the federal government. Most medical pot users get their marijuana from Health Canada directly through the mail. They pay between $5 and $12 per gram, according to Leaf Science

Despite the drug being illegal, Canadian authorities generally don’t prioritize marijuana law enforcement, and many cities in the country have taken a lax approach toward the plant. Dozens of illegal medical-marijuana dispensaries have cropped up in Vancouver in recent years, but the city’s police department has said it won’t be shutting them down.