So, you purchase something and type in your address and credit card details along with your contact number. That's about all the information the store needs to verify and ship your purchase; anything else is unnecessary information, most sites ask for date of birth, spouse details, number of children etc. as information for data banks, and it's really your choice to give out the information or not. Things like bank account numbers and other details should not be divulged at all. Keep your purchase private, you don't have to reveal too much about yourself; which in the hands of hackers can create loads of trouble.