just to reply on the issue of retailers who have a sign out saying "We do not accept 50s and 100s" -- what they are REALLY saying with their sign is, "We do not train our staff to recognize phony banknotes". counterfeiters LOVE these places because, as the Bank of Canada states and knows well, people generally do not counterfeit large denominations (viz.) the best news, of course, is that security features on the banknotes means fewer and fewer bogus ones.

i DO make it my business to tell shop owners their folly and have been occasionally rewarded to see them realize this and take down their sign right in front of me. the others... well, i am not sure about because i simply do not ever shop there again.