Door MathFox: Door Erik van Straten: Door veni: But overall, I think the core question is: to what extent or in what ways is DigiD a new means of surveillance? That is the least of my worries w.r.t. DigiD, if it is something to worry about at all. Use of the BSN (Citizen number) to combine data from multiple data sources is the biggest worry for privacy. Firstly, in most cases a name plus date of birth also uniquely identifies a person - just like a BSN. The IMO biggest problem with BSN's is that some people think that they are sufficiently secret to be used as a means of authentication (like knowing somene's BSN should grant you access to their health information, which obviously is rediculous). Secondly, BSN's get leaked all the time but I don't recall that Logius (the organization responsible for DigiD) was ever to blame. This does not mean that such an incident is impossible, but the chance of BSN's leaked elsewhere seems a lot bigger to me. Door MathFox: Any serious database contains errors and Dutch ...