In various contexts, a concern has been expressed, both implicitly and explicitly, that search engines in general, and Google in particular, may be using some system that obscures certain cultural content or emphasizes the Anglo-Saxon perspective, to the detriment of other cultures and languages. To put it in other terms, we present an exclusively theoretical approach to the idea that intensive use of search engines, which is so common now, represents a threat to cultural diversity. First, with the goal of putting our study in context, we present two previous debates on the dilemma of protectionism vs. the free flow of cultural products, and then analyse the most relevant characteristics of search engines (with a focus on Google) to determine whether they constitute a credible threat to cultural and linguistic diversity on the Web.