Picture this scenario: a special occasion and you have booked a meal for two for the evening. The restaurant requires an email address to confirm your booking, so you type in your Google mail account address and your booking is complete.
As you leave work, you want to check your route so you whip out your smartphone, go into your email, click on the restaurant's address hyperlink contained in the message, and a Google map flips onto your screen, flashing a blue dot to show you where you are and where you need to go.
During the course of your meal, both of you are racking your brains to try and remember the name of the actor starring in the film you watched last night. A quick Google check, and you have it.
As you leave, you need to double check the best way to get to the bus-stop, so again, you get out your phone. Handily, your map is still open but minimised as you unlock your phone, so you click on the map icon, the blue dot comes back and you figure out your route.
Knowledge is power
By the following morning, the chances are that if pressed, Google will know the name of the restaurant you visited last night. It will know where you were when you left to get there, and at what time, and likely, the route you took to get there. It will know what time you left. If asked what you talked about over dinner, Google would not be wrong if it was to answer "movies". Ask which film, and it is a dead cert - Google can name the film.
If you're an Android user, Google can know even more about you. The company's policy allows for it to know which numbers you call, and when, and for how long. Fancy ruminating on the day's developments on your blog? If you post through Blogger, it is yet another realm of your web life that the company can access.
"It's the power of that information to know and predict every aspect of your life with such control which is difficult," Dr Joss Wright, Fresnel research fellow at the Oxford Internet Institute, told Channel 4 News.
"We have little control over what they do. If I use my Gmail for work, then browse YouTube, I don't want my work Gmail getting advertising for what I looked at on YouTube."
The policy, which came into force on 1 March, allows Google Inc to collect information from users who sign up to a Google account. This includes personal details such as name and email address, and if the user provided a telephone number and credit details, it includes these two.
It can also collect information from users from Google services, such as Android, YouTube, or Blogger, and how they use them. It can collect and aggregate everything a user searches and how they use the service - as in, how long a person stays on a site for and the sequence of the sites that person visits.
In theory, it could allow for Google to assess your thought patterns, at least related to how you use the internet, which kinds of links you are likely to choose, whether you are the kind of person who likes long, drawn-out reads, or whether you are a click-a-minute kind of person.
"We use the information we collect from all of our services to provide, maintain, protect and improve them, to develop new ones, and to protect Google and our users. we also use this information to offer you tailored content - like giving you more relevant search results and ads."
A degree of this has already been taking place. Think of the number of times that, having logged on to your Gmail account, adverts pop up related to something you innocuously referred to in an email to your mother.
A spokesman for Google UK told Channel 4 News: "When you're searching, if you have been searching for a certain product, such as a recipe [this will bring up] more tailored ads.
"This now incorporates other general services, such as YouTube. If you search for something in a general search, then you may see a relevant ad on YouTube."
Google has added that none of the information is sold or shared with third parties, bar requests in the interests of the investigation of potential criminal activity by the authorities. The way in which targeted ads come up is that algorithms are generated as a code for what is searched for and used, and these are used to link to relevant adverts.
But the new policy has not come without its problems, for Google at least. EU authorities are concerned that such a mass conglomeration of personal tastes and information could constitute a breach of privacy. The EU's data protection authorities have asked the French regulator, CNIL, to investigate.
CNIL said it's "preliminary analysis shows that Google's new policy does not meet the requirements of the European Directive on Data Protection."
Moreover, the agency fears, Google Inc, which CNIL says represents more than 80 per cent of the European search market, around 30 per cent of the European smartphones market, 40 per cent of the global online video market, and more than 40 per cent of the global online advertisement market, is attempting to shoe-horn the policy in before privacy rules are tightened up as expected.
In the meantime, for the Google user, is there any way to avoid being watched?
Possibly, by searching for things on Google or YouTube without logging into any other account-based services first. Alternatively, by setting up different accounts, so that no one source can be traced, although some information will still be kept. Or by using Microsoft maps instead of Google maps. In short, by using the internet as an anonymous user, and not as an account holder, although there is still a chance that something will slip through the net.
A foolproof way is complete internet abstinence, which most would agree is near impossible. "That's the same as telling someone 'I don't have Microsoft Word, so I can't read that document'," Dr Wright said. "You're forced to use these services because they're so ubiquitous."
Google allows you to also tailor the amount of information which is used to target a user, through its settings. A user can view and edit ads preferences, and control who the information is shared with.
The onus, then, is on the legal challenge the company potentially faces.