The story continues. Here’s Bill Thompson’s distinctive take on it.

As we have seen with flu trends, sometimes the “interesting” knowledge that can be extracted is well-concealed until comparisons can be made with other sources, as it was the correlation between some search terms and the real-world data that mattered.

Of course Google has not revealed which search terms it analysed because doing so would undermine the model’s effectiveness.

Unfortunately it is being equally reticent about how it has ensured that the data its uses is properly anonymised so that users cannot be identified on the basis of their queries.

A letter from the Electronic Privacy Information Center (EPIC) and Patient Privacy Rights to Google boss Eric Schmidt has not been answered, leaving those concerned with online privacy uncertain over the broader implications of the project.

But as Cade Metz points out in an insightful article in The Register, we may all be happy to know that a ‘flu outbreak is coming, but what happens when the disease involved is more life-threatening and the government asks Google for the names and IP addresses of anyone whose search terms indicate that they are infected?

It’s not that I don’t trust Google. I don’t trust any company, government department or individual without a good reason to do so.

In the case of search engines that claim to protect my privacy I want to know just how they do it and will not accept vague reassurances.