Amazon.ca knows too much about us???? | Your stories | Discussion forum

Somebody might know more about this topic than me or has a logical explanation.

I was helping a friend to set up an amazon.ca account. No issues there.
When she started adding her credit card(s) as way of payments amazon.ca wanted to confirm she is rightful owner of those and wanted to send authentication code. Here it becomes Very interesting: Amazon.ca did offer to send a code to either her mobile phone or email address she uses ONLY for those particular FI!!!
- Does this mean amazon.ca has access to her FULL credit card/banking record?
-- If that is correct why would Canadian big banks allow such access???
- Are ALL Canadian credit cards (with all personal info) stored in one huge database amazon.ca can query at will?
- Any other explanation how can Amazon knows her mobile number and email associated with her credit card(s) if she Never provided it to them?