If you have something that you don't want anyone to know, maybe you shouldn't be doing it in the first place. If you really need that kind of privacy, the reality is that search engines -- including Google -- do retain this information for some time and it's important, for example, that we are all subject in the United States to the Patriot Act and it is possible that all that information could be made available to the authorities.
That was Eric Schmidt, the CEO of Google, telling you exactly what he thinks about your privacy. There is no ambiguity, no "out of context" here. Watch the video.