In e-commerce, the protection of user privacy from a server was not considered feasible until the private information retrieval (PIR) problem was stated recently. A PIR protocol allows a user to retrieve a record from a database while hiding the identity of the record from a database server. We explain a motivation for PIR by demonstrating ecommerce examples, where only PIR techniques help. Allout overview of what is done by the community is given without details of concrete algorithms. We conclude with future work, which is mostly aimed at making PIR practical.