We don't have statistics in Canada, but according to what Homeland Security or the FBI has published--I'm not sure which of the two, so I'd have to go back to my files--only about 2% of the people on the list have been intercepted, and the list in the U.S. is huge. We're talking tens of thousands of people. Not a single one of those persons was intercepted for being a terrorist threat or a threat to aviation. They were criminals with outstanding warrants, so the U.S. list has been used for giving the police more powers to get after regular criminals.
On April 29th, 2010. See this statement in context.