The Google TOS clearly states that they have the right to analyze your content in order for them to provide ads. This includes Gmail, Docs and whatever else you

The Google TOS clearly states that they have the right to analyze your content in order for them to provide ads. This includes Gmail, Docs and whatever else you may use. When it comes to search they save your search history for customized searches. Let me put it this way: they don't target those ads so precisely by not having any information on you. On the contrary, they have lots of info. How safe and how anonymous that info is, that's up for debate.