Can We Sniff Wi-Fi?: Implications of Joffe v. Google

On 27 December 2013, the US Court of Appeals for the Ninth Circuit issued an opinion that intercepting data from unencrypted wireless local area networks--Wi-Fi sniffing--can violate the US Wiretap Act. The case centers on a Wi-Fi sniffer that was present in Google Street View vehicles that roamed the US between 2008 and 2010 and that were permanently recording every unencrypted Wi-Fi frame that they intercepted. Although the Wiretap Act has a broad exemption for intercepting radio communications that are generally accessible to the public, the Court ruled that Wi-Fi is not a radio communication. The ruling, if it stands, will significantly impact computer security education, in which Wi-Fi sniffing is a common student exercise; security practitioners, who frequently sniff for security assessments; and computer security research, which has traditionally used collection in the wild as a way of finding vulnerabilities.