The Orwellian overtones are clear. And European data protection authorities are, rightly, concerned about the implications. Preliminary analysis, commissioned from the French regulatory authority, suggests the scheme may not conform to EU law, concluding that Google's explanation of how the data will be used is too difficult to understand "even for trained privacy professionals".
Ultimately, however, the changes may turn out to be less alarming than they initially appear. After all, Google already matches ads to the queries entered in its search engine. The same applies to Gmail, to the Google Plus online sharing system, and to video recommendations on YouTube. It is hard to see how bundling everything together will make matters qualitatively worse. And, in fairness, no actual human being has access to any individual's data; matching ads to content is done entirely by computer algorithms.
It is also worth remembering the bargain one strikes online. One of the primary reasons for the popularity of Google's services is their relevance. While targeting advertising more narrowly may seem creepy to some, many will rejoice in the additional usefulness. Equally, given the commercial realities of service provision, a few personalised ads may be a reasonable price to pay for the range of Google offerings.
That said, there is still a balance to be struck between the interests of advertisers and those of internet users. And while Google's latest tweaks may yet be deemed an acceptable compromise, elsewhere in the online world there are developments of a darker hue.
Changes being introduced by Facebook are a case in point. Critics of the social networking site's newly introduced "timeline" feature – which encourages users to post their entire life history online – claim it makes it far more difficult for people to assert what the EU data commissioner has called "the right to be forgotten". Once private material based on anything from location, to email conversations, to present and historical searches, has passed into the public domain, it is nigh-impossible to erase.
Facebook also plans to end the easily ignored display adverts at the side of its webpage, instead allowing advertisers to stream messages into the posting, photos and updates of users' online friends. Marketing messages may show up unsolicited if someone has previously interacted with a brand. And ads will also now be streamed on to mobile devices – which count for around 30 per cent of Facebook use – for the first time.
Clearly caveat emptor must apply online as much as anywhere. But the changes from Google and Facebook also make a broader point, underlining once again the caution to be exercised around online activities. And what is clearest of all is that regulators must ensure internet users are not blinded with technical details.
We all must make decisions about what to disclose, when and to whom. To do so, we need to know, in simple terms, what data is being collected, how it is being stored, and how it will be used. The lesson from recent developments is that, for most people, it is too difficult to grasp what new systems mean, and too complicated to opt out of them. That must change. Confidence in a digital future depends on the certainty that our privacy is not at risk.