You've raised the issue of accuracy. Canadians give up a lot of information voluntarily. Anybody who does a political poll, market research, or product testing knows they give up a lot of valuable information, some of it very personal in nature.
Take political polls. I worked in market research for a long time, actually. A sample of 2,000 Canadians giving voluntary data is accurate to within about a percentage and a half, 19 times out of 20. Is that good accuracy?