Most people assume that if you're born in Canada, to Canadian parents, you're Canadian. Unfortunately, things are not always so simple.

Under CIC'S interpretation of the Citizenship Act, thousands of Mennonites living in Canada are in danger of losing their Canadian citizenship because of a legal technicality in Latin America, where almost 7,000 of their ancestors moved in the 1920s.

The Mennonites went to Mexico and Paraguay looking for a place to live without government interference in their lives, but they have been trickling slowly back to Canada ever since. Many of them married while living in Mexico, and that's what is causing the problem now. They were married by the church, and Mexico doesn't recognize church marriages as being legal. That means their children were born out of wedlock, and they — along with their grandchildren and even great-grandchildren — are not eligible to be Canadian citizens. The Mennonite Central Committee says that while the number of people affected is not known, up to 30,000 Mennonite Canadians could be at risk, plus an unknown number of other people.

Anna Fehr, 20, is the grandchild of one of those couples. She was born in Mexico, but moved back to Manitoba more than a decade ago with her family. Last year, she got a letter from the government, saying she's not a Canadian.

"Your grandfather is considered to be born out of wedlock and doesn't have a claim to citizenship," said Fehr. "Consequently, your father is not entitled to Canadian citizenship, and you can't claim citizenship under your father for [the] same reason."

Bill Janzen, director of the Ottawa office of the Mennonite Central Committee, said the situation has become confusing.

"It comes as a major surprise when someone born in the 1960s received [his or her] Canadian citizenship. They then had children in 1980s, grandchildren in 2005, and all of a sudden it's discovered the person born in the 1960s was not born in wedlock," said Janzen. "So those who are in Canada when they discover this, government usually does not deport them; it looks for a way of getting them reinstated. But it's a cumbersome, and sometimes expensive and very inconvenient process."

The leading court case on citizenship was established by another illegitimate child, Mark Donald Benner, who was born out of wedlock to a Canadian mother. In 1977, the Supreme Court of Canada ruled ruled that the 1947 law violates the Charter of Rights and Freedoms by discriminating against both women and children. For seven years, CIC was forced to accept people like Benner, but officials convinced the court to limit the ruling to seven years, giving CIC time to rewrite its policy. Instead, in 2004, CIC reinstated the old policy, and once again, is rejecting citizenship for children born out of wedlock to Canadian mothers before 1977.

Charles Bosdet of Cape Breton, N.S., is another example of someone who has had trouble with this interpretation of the act. He was born in Winnipeg to two Canadian parents and his parents were married at the time, but CIC argued his grandfather — a First World War veteran who fought at Vimy Ridge — might have been born out of wedlock.

Under the 1947 act, if a child is born in wedlock, his or her citizenship is determined by the father's citizenship. If the child is born out of wedlock, then the citizenship is determined by the mother. Bosdet says that means anyone who can't prove his or her ancestors were born in wedlock could have their citizenship questioned today. "Can anyone be safe if this rogue elephant decides to challenge your citizenship?" he asks.