Rather than buying into the hype surrounding the Federal Communications Commission's investigation of how Google conducted its controversial Street View survey, let's start with a few facts. I know that many of you, especially those who think of themselves as privacy advocates, are going to hate what I have to say.
But the truth is Google did not break the law in the United States when it collected WiFi access point data. While it certainly did nothing to make the FCC's investigation easier (thus the $25,000 fine for obstructing the probe), it's not even clear that the law required Google to help the FCC.
So here are the facts. First, WiFi signals are unlicensed radio transmissions. While intercepting private radio transmissions isn't legal, that's only when those transmissions are clearly intended to be private. In its examination of the Wiretap Act, the FCC noted that the Act provides, It shall not be unlawful under this chapter or chapter 121 of this title for any person ... to intercept or access an electronic communication made through an electronic communication system that is configured so that such electronic communication is readily accessible to the general public.
What this means is that if a person doesn't encrypt his or her WiFi, then it's readily available to the general public. And it is. WiFi equipment is ubiquitous. If a WiFi signal is unencrypted and the SSID is readily available, then it would appear that listening in on any communications through that signal isn't against the law. Because of the way that theCommunications Act of 1934 and the Wiretap Act are written, the part about communications being open to the general public applies to both.
This is consistent with the FCC's practice since its inception. Radio transmissions have always been open for others to listen to unless something specifically prohibited it. When I got my first commercial engineer's license from the FCC nearly 50 years ago, it was part of the material we had to study. At the time, it was clear that there was no expectation of privacy in radio communications unless you did something to make your communications private or if the FCC specifically said they were private.
This practice held up through the first cordless phones, which transmitted analog signals at 49MHz and could be listened to by anyone with a radio that would cover that band. The same thing held true with cell phones that transmitted clear analog signals. Only when the FCC required that manufacturers stop making cell phone frequencies available on general-purpose radio receivers was there any expectation of privacy, and even then it was legal to build your own receiver to listen in on cell phone calls.