Google will now be able to share all the information between all of its services to create a user-profile and generate a huge set of detailed statistics. Google claims this information is used to ensure that you have the best possible experience and to generate adverts that are suited to your tastes.
However, the skeptics say that knowing so much about your life is an invasion of your privacy, with some even saying the move breaks the data protection laws. The idea that Google will know your location, what you search for and what videos you've been watching is a scary thought , but 3G think we just better get used to "Big Brother" watching us.
You can easily avoid some of the data sharing by not logging into sites where you don't have to. For example, don't sign into your Google Account while using Youtube or Google Search.