That, of course, would be very bad legal news for a whole class of technologies that use Wi-Fi transmissions for tracking customers in-store, and in some cases just for electronically counting them as they come in the door. That's wiretapping? There's a lot wrong with how Google ended up with lots of fragments of ordinary people's e-mails and web searches. But there's a real difference between tapping into actual content and just decoding elements of a Wi-Fi signal's "wrapper," which is the first thing any Wi-Fi access point does. If some court or other doesn't straighten this out, we're all wiretappers sooner or later.
As if retailers didn't have enough conventional privacy concerns, now even touching customers' Wi-Fi may have more legal problems than previously thought. On Sept. 10, a federal appeals panel in San Francisco ruled that Google (NASDAQ:GOOG) violated the Wiretap Act when its StreetView cars scooped up lots of Wi-Fi data from unencrypted connections. But in its convoluted inspection of what "radio" means (did you realize that if it's not audible, it's not radio?), the judges actually open up the possibility that even capturing the MAC addresses that mobile phones send out over Wi-Fi might be Wiretap Act violations.