On reading the healding to this article I found myself ready to be outraged at this appalling misuse of data entrusted to the goverenment for purposes other than it was orginally intended.
On actually reading the article, however, I find it very difficult to be angry about it. Indeed, I am even in favour of it. The key word here is anomymised. Provided that is genuinely the case then I can see huge value in the medical community having access to a large pre-existing database of DNA samples.
However, we need clear ground rules to preserve anonymity. If all that is given is the samples themselves then there is no big deal, but I can see legitimate reasons for wanting the ages of the individuals or where in the country they live. If we are not careful it would end up with the data not being very anonymous at all.
So what to give? Maybe a bracketed date of birth such as just the year rather than an exact date, a vague region such as Midlands or North West, and since the gender is easily determined in any case supplying that as a convenience would do no harm. The data would have to be taken from periodic (e.g. annual) snapshots of the database to prevent very new samples being identifiable by cross-referencing with previous requests. If you provide much more than that you run the risk that the supposedly anonymised data would be nothing of the sort. If more data is needed then you have to acquire your samples from somewhere else, preferably where they actually volunteered their details.
So on balance, a guarded welcome. However, what is needed urgently is for ground rules of the kind I have just wished up to be firmly established and the data to be offered on a take-it-or-leave-it basis. Those guidelines need to be in the public domain so that we can all see that the data given is as anonymous as we are told it is.