This article argues that search engines raise not merely technical issues but also political ones. Our study of search engines suggests that they systematically exclude (in some cases by design and in some, accidentally) certain sites and certain types of sites in favor of others, systematically giving prominence to some at the expense of others. We argue that such biases, which would lead to a narrowing of the Web's functioning in society, run counter to the basic architecture of the Web as well as to the values and ideals that have fueled widespread support for its growth and development. We consider ways of addressing the politics of search engines, raising doubts whether, in particular, the market mechanism could serve as an acceptable corrective.