In 2007, Google bought online ad network DoubleClick, which uses
cookies to collect and store data about Google users from their
browsing history, to best place clients' ads. This past June,
Google revised its privacy policy to state that users'
activities on other sites tracked by DoubleClick "may be
associated with [their] personal information." This
change means that Google now has the ability to compile a
comprehensive profile on any user who opted in, based on his/her
browsing habits across any device used to access Google's
services (e.g., Gmail, YouTube, etc.), and made up of personally
identifiable information collected from those services.
The change is optional for anyone with an existing account
(accessible through the "Activity Controls" menu), but is
set as default for any new account created from June onward.
Further, users who have opted in to share their data with Google
can opt out at any time. Google has even highlighted the recent
changes to its pr
