This project is being crawled all over by the paranoid, the conspiracy theorists, Chicken-Lickin', fanticists, and the deeply, deeply concerned looking for yet another topic to worry to death.
It is in nobody's interests that there be a breach of privacy. Everybody involved knows this. Far better than all the people getting on their hind legs and screaming about it. One has to wonder are they really concerned about people's privacy, or do they just imagine they are? Is protest what they really want to do, do they just to wreck a big project regardless of its potential benefits?
Some quite bright people get involved in this kind of research, patient confidentiality is one of their overarching principles, they know a great deal more about how to do that than the people protesting.