If you are worried about misuse of information from a DNA search, think of those who served in the Military. I know the government knows way more about me then I might like, but I also know that I got to do some interesting stuff in the Military. The DOD has my finger prints in printed form, electronic, has a file on where I have lived, worked and where I am now. What more could a DNA test provide? OH and I had a security clearance that took the DOD and FBI to clear me. You want to see the file they have on you, mine was 4 files, each about 2 plus inches thick. Heck they even knew as a kid growing up I was bullied and a runt, had a hard time accepting the 6 foot 4 inch guy across the table was once a runt. Working on a neighbors farm for 10 years puts muscle on a person, didn't hurt I ate like a horse.
One last point if you don't think that everything we write on the net isn't being scooped up and filed, along with every phone call, purchase then you are not paying attention.