Like emails and documents stored in the cloud, your prescription medical records may have a tenuous right to privacy. In response to a lawsuit filed by the American Civil Liberties Union (ACLU) over the privacy of certain medical records, the US Drug Enforcement Administration (DEA) is arguing that citizens whose medical records are handed over to a pharmacy — or any other third-party — have "no expectation of privacy" for that information.

The administration's argument plays off of the "third-party doctrine," which says that handing over a document to another party — even if that just means sending an email through someone else's server — revokes any fourth amendment right to its privacy. The DEA also argues that a 1977 Supreme Court ruling should be read to say that "there is no constitutional right of privacy to prescription information" — though the ruling itself doesn't say that quite so explicitly.

"The most deeply private and sensitive information about us."

The ACLU disagrees with both of the DEA's arguments. "The information we share with our doctors ... constitutes some of the most deeply private and sensitive information about us," Nathan Wessler, an ACLU attorney, writes in a blog post on the case. "Just because we trust our doctors and pharmacists with our medical information doesn't mean the DEA should be able to easily access it too."

The third-party doctrine has been a continuing concern for professionals handling sensitive data, such as lawyers and physicians. In this case, the DEA compares a patient handing prescription records over to pharmacy, to a homeowner handing electrical usage information over to a power company — something that a US appellate court recently found to not require a warrant. The ACLU disagrees with this doctrine being applied in sensitive situations, and notes that the DEA's comparison here is "absurd."

The ACLU's suit represents complaints from four patients, whose prescription records are stored in a state database used to assists doctors in preventing drug abuse. The DEA has been requesting information from this database through subpoenas — rather than a probable cause warrant as a state law reportedly requires — and the ACLU's clients have objected to the practice. According to the ACLU, all four patients have prescriptions that would detail personal information about them, including gender identity and mental illnesses, underscoring exactly how revealing such data can be. For now the suit remains early and ongoing, as both sides continue to file briefs after the initial complaint was raised earlier this year.