Badbullgator is right. The results of DNA testing can serve many purposes. I am most concerned about a DNA database for medical purposes... care (or denial of care) based upon famial predisposition.
I know only a little bit about DNA testing (Y, i.e. male) for genealogical purposes. I do know that when you test for only 12 markers, males can match 100% in those first 12 markers so relationships can't be relied upon in a 12-marker test. You have to test for more. My husband took the 67 marker test to determine matches with males who had the same common ancestor.
Brothers with the same father could have the same DNA results or they can be off a marker or 2 when taking the 67-marker test. If they have the same mother but different fathers, they are not going to match.
"There is very little justice in this world; only the law, which is a very poor substitute."
Peter Hathaway Capstick