How much is too much? It's a question that crops up time and time again as companies attempt to extract increasing amounts of personal information from us.
Storing the results in huge computer databases, it is difficult for us to keep track of who knows what - but it’s also a symptom of the open society in which we have found ourselves living.
With the government intending to share our patient medical records via the care.data programme – a gigantic project which entails digitising England's entire medical history and storing it in one place – the issue of privacy is very much a hot topic.
Google CEO Larry Page recognised this at a TED conference in Vancouver earlier in the week when he spoke of his desire to make the medical records of patients open for sharing. He said it would be “amazing” if everyone's medical records were available anonymously to research doctors and he claimed the move would save 100,000 lives this year.
For him, though, the biggest hurdle was the hang-up most of us have about giving too much away, something he blamed, in the United States at least, on the snooping activities of the NSA. Page pushed forward his thinking that we need to take a more relaxed approach to privacy and allow more of ourselves to be shared.
This would, of course, suit Google. It has made a living out of harvesting and sharing data so if people were more chilled out about their personal information, then its job would be made even easier.
Certainly, there are parts of our lives that we don't seem to mind divulging to the world. Millions visit Facebook and Twitter, telling the world their date-of-birth, letting people know when they are going to be away from home and posting images of themselves in all sorts of situations, good and bad.
But it seems the intricacies of our medical history are felt to be more personal, even though sharing such details makes sense. There is general agreement that sharing medical data will benefit patients and help lead to vital discoveries. Researchers would not have worked out that asbestos exposure was causing the terrible cancer, mesothelioma, had they not been able to access patient data and work out the backgrounds of the people presenting with the illness.
Sharing data – which extends to family history, vaccinations, referrals, date-of-birth, postcodes, NHS numbers and gender – lets researchers discover patterns and work towards beating major illness. It does this far more effectively than sharing a face without make-up on social media ever would.
The NSA has only been part of the problem though. Distrust over Care.data is more to do with governments' track records when it comes to computer systems.
People worry that their medical records will be traceable, that they will be used by third-party companies such as insurance firms to work out premiums of people in certain areas. They fear hackers getting their hands on information and their privacy being compromised.
But Google itself has to take a proportion of the blame. You only have to look at what the company does with the current data it holds and how it obtains it to figure whether our most vital of details would be well managed and cared for, regardless of who is doing the storing.
A class action lawsuit in the US was brought against Google in May last year in response to its repeated scanning of Gmail for key words that it can use for the targeting of adverts. A few months later, Google claimed UK law didn't apply to the company when it was faced by a group of Safari users attempting to sue over privacy infringement.
Google understands the power that sharing data brings, not least to itself, given that its fourth quarter results for 2013 showed $16.86 billion in revenue. It creates products that benefit the masses – from internet searching to, increasingly, home automation – but, in doing so, it finds out more and more about people. Its empire extends to the Chrome browser, maps, YouTube, news, word processing, online storage, calendars, blogs, email, Android and so much more. With its Nest acquisition it will even know how you like to set your thermostat.
This harvesting of data has continued for many years without much intervention and, in September 2013, such practice was even seen as agreeable by the Commons Culture, Media and Sport committee who said: “We do not think the targeting of appropriate advertising – essential to so many business models – represents the greatest threat to privacy.”
So we are faced with a position where Google, who we trust, is doing things with our data that perhaps, on reflection, we would rather they didn't. We are also faced with a government, who we seemingly don't trust as much, wanting to share key data about the health of everyone in the UK and backing the harvesting of information for the use of advertising.
From this, we should be learning lessons. People will be more relaxed about privacy if they are reassured that their personal data will be treated with the utmost respect. In the case of Care.data, there should be no selling of data to third-parties such as the drug and insurance companies and patients should know exactly how and where their data is being used.
Data has to be treated with sensitivity and not as a commodity and companies such as Google should be even more open about what they are doing with data and make it easier for people to read and delete, if need be, anything stored about them. Transparency is key.