How would you feel about your DNA being kept on a national database?

Regardless of whether someone has committed a crime or not do you agree or disagree with DNA being held in this way?

Is it an invasion of privacy or do you believe that if you have nothing to hide then it shouldn’t be an issue?

One of the panelists on last weeks Question Time (BBC) said that not only can this be used to prove a persons guilt but it can also be used to prove a persons innocense.

Thoughts?