A friend mentioned contributing DNA to the National Geographic Society's Genographic Project "which is seeking to chart new knowledge about the migratory history of the human species by using sophisticated laboratory and computer analysis of DNA contributed by hundreds of thousands of people from around the world."
I got curious about the privacy implications of providing genetic materials to the project, whose goals are certainly laudable. Having reviewed the project's privacy page, it was unclear to me whether the DNA would have to be made available in response to a lawful subpoena related to civil or criminal proceedings for personally identifiable genetic information. So I asked them via email. They were kind enough to respond as follows (which I have their permission to publish):
The results of the Genographic Project identify ancestral migration information only. They cannot be used to identify someone in criminal proceedings. As stated in our section on ethics and privacy of our Frequently Answered Questions, the results of the Genographic Project Public Participation Kits can be accessed only by the respective participant or by someone else to whom the participant gives their randomly generated Genographic Project ID (GPID) number. No one can link a participant's name or other contact information to the sample that was provided to the Genographic Project unless they have the participant's GPID. To help protect the privacy of participants, the project does not associate any personally identifiable information about a participant with this randomly assigned password. As noted in the "Frequently Asked Questions" section of our website, National Geographic may disclose participant information when doing so is required by law. However, because National Geographic does not retain a participant's randomly generated GPID number, National Geographic cannot associate a participant's results with contact information the participant may have provided when ordering, such as a name or shipping address.
If a participant chooses to request further genetic testing from National Geographic's partner, Family Tree DNA, for purposes other than the Genographic Project, the participant will use their GPID to permit Family Tree DNA to access the sample of cheek cells they provided. Family Tree DNA has committed to National Geographic that it will protect the confidentiality of every GPID and that it will safeguard and use the number only for purposes of the further testing that the participant has requested. National Geographic will discard public participant samples at the conclusion of the Genographic Project unless participants have voluntarily transferred their individual samples to Family Tree DNA for optional further testing.