It may seem banal, but how much energy a household used at a particular time is actually intimate information concerning someone's private life. That's the argument raised by activist groups the Electronic Frontier Foundation and Privacy International in a recent court filing.
But the move highlights a more general trend: As citizens bring more and more data-collecting devices, such as the Amazon Echo or Google Nest into their homes, those so-called "smart" gadgets come with a host of questions, concerns, and problems around who can access that data, and their impact on privacy.
In 2012, the city of Naperville, Illinois, began replacing analog energy meters with smart equivalents. The Naperville Smart Meter Awareness, a local activist group, filed a lawsuit in the Northern District of Illinois against the city, arguing that the meters endanger the health and invade the privacy of residents. The district court held that Americans have no reasonable expectation of privacy in their aggregate smart meter data.
The EFF and Privacy International are pushing back against that ruling.
"Whereas analog meters provide a single monthly measurement of cumulative household energy use," the new filing reads, "smart meters—by measuring energy use at much shorter intervals; here, every 15 minutes—provide information regarding not only how much energy was used, but also the time at which it was used."
"With 15-minute readings, one can see when people go to bed, get up in the morning, or go to school or work," the filing continues. "One can see 'weekday' and 'weekend' patterns; and so on."
The groups argue that smart meter data is entitled to Fourth Amendment protection—that is, obtaining it for law enforcement purposes should require a warrant with probable cause—and compare it to thermal imaging data. In another case, a judge ruled that obtaining this sort of information constituted a "search," and so was protected under the Fourth Amendment.
As for smart meters, the district court's previous ruling that citizens don't have a reasonable expectation of privacy over such data relied on the idea that residents voluntarily transmit detailed energy usage information to utility companies. However, that's arguably not the case.
As the joint EFF-Privacy International filing explains, in many cases smart meters are mandatory, or come with monthly opt out fees. "Consumers thus often have little choice but to share smart meter data with their utility companies—that is, if they wish to have electricity in their homes," the filing reads.
The filing points to figures from the US Energy Information Administration, which says that in 2015 over 57 million smart meters were installed in homes.
"The district court's holding that Americans have no reasonable expectation of privacy in aggregate smart meter data as a matter of law threatens the privacy of these 57 million and counting American households," the filing reads.
The expectation of privacy problems stretches across many different types of technology and systems. Last year, a judge ruled Tor users had no such expectation because they allegedly "voluntarily" gave their real IP address to a third party.
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