This, folks, is how the Nudgers and so-called "libertarian paternalists" work. From the Tory Manifesto's (rather brief) passage on civil liberties:
The indefinite retention of innocent people’s DNA is unacceptable, yet DNA data provides a useful tool for solving crimes.
We will legislate to make sure that our DNA database is used primarily to store information about those who are guilty of committing crimes rather than those who are innocent. We will collect the DNA of all existing prisoners, those under state supervision who have been convicted of an offence, and anyone convicted of a serious recordable offence.
Got that? You'll have to remember to ask the state to remove your DNA from the database. Which is fine and all about personal responsibility and so on. But the libertarian might think the presumption should be that innocent people should not be on the database at all. The Conservatives appear to think differently and this would seem to be a manifesto pledge crafted to help the government maintain as many samples on the register as possible.“
We pushed the Government to end the permanent retention of innocent people’s DNA, and we will change the guidance to give people on the database who have been wrongly accused of a minor crime an automatic right to have their DNA withdrawn.
And what on earth does "primarily" mean in the context of using the database "to store informatio about those who are guilty of committing crimes rather than those who are innocent"? I suggest it means that there will still be many, perhaps millions, of innocent people on the English DNA database and that these people's DNA will remain on file for years and years.