Ah, when I saw the title I thought this might be about medical data privacy concerns.
I'm vaguely aware of some of the gene pools I'm connected to, thanks to bits and pieces of documented family history, but I didn't feel the need to re-connect with any of them.
Perhaps I'll try DNA sequencing out of sheer curiosity, but not before I try to sell my data first -- there's some peculiar bits in there. Might not work out, but worth a try.