Under Google's new policy, user data from all Google-owned sites and products -- including YouTube, Gmail, Google+, Blogger, and Google's search engine -- will be consolidated and shared across those sites.
For example, a Google user's search-engine queries will be used to determine what advertisements appear when a user accesses Gmail. The data will also be used to create customized search results.
The policy change will give Google access to data that some users may consider personal, such as location, age, and interests. Search terms and Internet activity can also reveal a user's religion, health issues, and sexual orientation, the Electronic Frontier Foundation points out.
Here's how to "delete" your Google web history, according to the EFF:
This must be done to all Google accounts for which a user doesn't want her information shared.