Julia Angwin found out Google had been saving her 26,000 searches per month, and they’re doing the same to you. For private search, check out Ixquick.com, the world’s most private search engine. Read Angwin’s story of her investigation into Google and other web sites on NPR.
You can ask Google what do they have on you and they do actually provide a pretty comprehensive answer. I was able to see all of the Google searches I have conducted since 2006, which was a lot of Google searches. It turns out that I had been doing about 26,000 Google searches a month. So I could see them by day, I could sort them by type of search — shopping, maps — and I was amazed at how revealing they were. I could reconstruct all the crazy leaps that my mind makes on any given day where one minute I’m working on an article and the next minute I’m suddenly shopping for shoes for my daughter and a minute later I jump onto another topic. It was a little disturbing to see what my mind does.