On August 16, the 7th Circuit Court of Appeals issued its decision in Naperville Smart Meter Awareness v. the City of Naperville finding that smart meter data collection is a "search" under the 4th Amendment, but allowable constitutionally because the search is "reasonable." The court noted that smart meters play an important role in grid modernization, in which the state has a legitimate interest. The court balanced this state interest for grid modernization with the intrusiveness of the smart meter search.

The "search" is the collection of "[electric] load signatures" from various home appliance and power uses within a home on a fifteen minute interval. Naperville Smart Meter Awareness, a group of concerned citizens, argued that personal intimate details about activities within a house are being collected by the municipal utility's smart meter technology. These details include sleeping patterns, travel patterns, eating patterns, appliances and technology within the house.

While finding that the search was reasonable, the court's opinion highlights factors which could change its opinion. The court provided that a shorter time interval for collection of electrical data could change its analysis. So for instance, if the smart meter technology collected data every five minutes (rather than fifteen) the search could become overly intrusive and tip the constitutional balance in favor of consumer privacy. The court also drew a sharp distinction between the government's interests in grid modernization, and that of law enforcement's interest in the data. If the data collected by smart meters was shared with or used by law enforcement, the court suggested this would also change its analysis.

In conclusion, neither utilities implementing smart meter technology, nor privacy advocates should be overly enthused or disheartened by Naperville Smart Meter Awareness. The 7th Circuit provides a solid constitutional framework for state policy-makers and regulators as they continue to tackle the issue of smart meters and consumer privacy.