[vertex-four]

A lot of things end up being tied to your ID number, and it becomes very difficult to limit the collaboration of companies to create a dataset about you, never mind making it easier for the Government to track people en masse.

[pisarzp]

Lack of ID card doesn't stop UK to share all your data with private companies, like in case of care.data and now also HMRC data. I never felt as tracked as in UK, where all companies know where I live and lived for last several yers.

On the other hand in Poland we do have mandatory ID card, and companies still don't have that much access to your data.

[sergiosgc]

I'll have to break it to you then: it's exceedingly easy to get the same use of data without an ID. The lack of national ID does not protect your privacy.

[vertex-four]

I said easier, not foolproof. Just a postcode and some other piece of data is often enough to tie a record to an identity.

There's a difference between possible and building a system specifically to help it happen.

[sergiosgc]

The feeling of protection hinges on how easy it is. A bit over ten years ago I was working in database "cleaning": merging databases from different organizations[1] into one coherent dataset. The data volumes were large, but other than that it is a simple task with low error rates and one which absolutely does not need global unique IDs.

This was ten years ago. The task only got easier since then.

On the flip side, the lack of national ID has inconveniences. How do you authenticate yourself when selling your house?

[1] Ethical work. These were needed either after mergers or because of the MS Access syndrome, where every department designed their own customer database.

[xerophtye]

Yep, FB and twitter doesn't need your national ID card number to know more about you than your spouse does