Asa Dotzler, Mozilla's director of community development, used his personal blog to urge Firefox users away from Google and to use Microsoft's search engine Bing, instead. Dotzler cited privacy concerns, specifically pointing to comments recently made by Google CEO Eric Schmidt.
Google's philosophy is that the more open information is, the better it is for everyone, especially the search giant, which makes money by organizing said information and then displaying as relevant as possible ads beside it. Microsoft, on the other hand, while still a business that like, any other, wants to make money, has a long history of dealing with privacy concerns and regulations, so it's eager to avoid potential issues if possible. Dotzler, a 10-year-veteran at Mozilla, is saying that if you care about your privacy, remember that Bing is better than Google, at least in that department.