Google has launched a new feature called Account Activity, that summarizes what you have been doing with Google’s various products including who you email, what devices you use and where you’ve been. Users who sign up for the service will receive monthly email reports about the Google services they use and how they use it. Users can also view these reports at any time by logging into their account and accessing their Account Activity page.
Account Activity is an alarming insight into how much information a signed-in Google user actually hands to the company. Among other things, the monthly report will detail the number of emails you've sent and received, the number and types of searches you've conducted while signed into your Google account, the places that you've signed in from and the different platforms and operating systems you've used while signed in.
Account activity can be actually useful in some cases, for instance, to keep track of one’s usage and catch any misuse. For example, Account Activity can help users see if anyone has been signing into their Google accounts on locations where they don't visit or from devices they don't own, and thus give them the ability to change their password to stop unauthorized use.
Account activity is an opt-in service. Since opting out doesn’t means Google will stop tracking you, it’s better to just opt-in and find out how much Google knows about you. Besides, stats about one’s activities is fun.
[via Google Blog]