The new policy allows Google to integrate the information from all of the services you use to learn more about you. They are not collecting any new information, just sharing that information between the various services. This data can include search queries, calendar appointments, contacts, preferences, and any other information that is in the Google system.
What can you do about it? The only way you can fully opt out is to delete your account. This article from the Washington Post provides the steps.
If you want to continue using various Google services here are some things you can do to isolate your information:
- Make sure that you are not logged into your Google Account when you search.
- Setup multiple Google Accounts using different email addresses. Use each account for only specific services.
The Electronic Frontier Foundation has very detailed information about the changes and steps you can take to protect your information.
For more information: