We have gang problems here and Granville Street is where they decided to pack all the bars in the late 90’s - for some reason. So one chain installed something like this and used it to keep out known gang members and anyone that was involved in a fight in the bar or that caused trouble outside. They just flagged you in the computer and it throws up an alert if you try to enter.
It’s in no way mandatory and is only at the big name bars. And might not even be legal:
Yelp is on it though: https://www.yelp.ca/search?find_desc=no+id+bars&find_loc=Vancouver%2C+BC
