Over the last years it has become apparent that privacy issues become more and more important when accessing data sources either on the Web or by database management systems. That is, the user does not only want to hide the query, but also the result of that query from others. In the past the problem of querying a database privately was solved by organizational rather than by technical means. In this talk we describe the problem of querying databases privately more formally and discuss existing solutions from the area of private information retrieval (PIR). The lack of efficiency and scalability motivated us look for alternative approaches using a so called �secure co-processor� (built by IBM). We introduce a set of algorithms that take advantage of the (physical) properties of the co-processor and show which algorithms are necessary to guarantee privacy for database queries. In the last part of my talk I briefly describe our vision how to extend the current privacy approach to location-based services, in particular to moving objects such as vehicles (cars).