That would be a concern. There may be technological mechanisms, encryption and so on, that would help to inhibit the risk of leaks. Currently, the only country that Canada engages in so-called automatic information sharing is the United States. We exchange bulk taxpayer information, mainly with respect to U.S. or Canadian residents engaged in cross-border portfolio investments. So if you open a bank account at the Bank of America in New York City, and it generates portfolio interest payments, the financial intermediary is mandated to collect it. It's shipped back and the CRA reviews it. That process has been going on for at least a couple of decades. To my knowledge, there haven't been any leaks. I think it may be possible to create this extranet and secure it from outside access.
On February 17th, 2011. See this statement in context.