When a shopper shares their email address at the cash register — to receive an electronic receipt, rather than a paper one — do they really know where their details are being sent?A CBC News review of Facebook user data suggests a variety of well-known retailers in Canada have been sharing customer information with the social media platform's parent company to gain marketing research in return. Purchases from department store giant Hudson's Bay, athletic apparel chain Lululemon, electronics retailer Best Buy, homeware store Bed, Bath & Beyond and beauty products chain Sephora all appeared in the Facebook data seen by CBC. "It's important we become more aware of the datafication of our lives," Wong, the UBC professor, said, referring to the way personal information is increasingly treated as a commodity