If the DNA was gathered for one specific purpose like this and not kept on file, I think that's pretty unobjectionable. As soon as it's on file in a database,

If the DNA was gathered for one specific purpose like this and not kept on file, I think that's pretty unobjectionable. As soon as it's on file in a database, though, there's potential for uses further and further removed from those envisioned by the owners when they gave the samples.