It is possible to identify anonymous customers with only data about four purchases.
Scientists showed they can identify you with more than 90 percent accuracy by looking at just four purchases, three if the price is included – and this is after companies “anonymized” the transaction records, saying they wiped away names and other personal details.
My daughter came home yesterday and told me about a web site that presents information about people. We typed in my name, which is fairly unique, it displayed information about where I have lived. She was alarmed. The information was obtained by publicly available knowledge, such as home purchases. There is no privacy anymore. She better understands why I do not want her to use her full name in usernames, such as email.