Whenever I've looked at public data websites like Gene Expression Omnibus or The Cancer Genome Atlas, it seems like SNP datasets are restricted access. I vaguely understand that this is related to privacy concerns, since a SNP profile could theoretically uniquely identify a person. However, this seems ridiculous because to uniquely identify the person from SNP data, you'd need the person's genome or SNP profile. These are not things that can be obtained easily and covertly, or legally without consent. Furthermore, such a policy of burying SNP data in a layer of red tape and requiring a separate request to be filed for every specific use discourages exploratory research and data mining.
Why is there so much concern about what seems to be such a theoretical issue? Is there anywhere were large amounts of de-identified human SNP data are available for data mining purposes without layers of red tape?
EDIT: I'm mostly interested in case-control SNP data, which seems particularly hard to find.
A relevant article: "Genomics and Privacy: Implications of the New Reality of Closed Data for the Field"