In 2008, Google applied to patent a system that analyzes the environments surrounding mobile phones -- temperature, humidity, sound -- by way of sensors embedded in those phones. The technology would be mainly used, Google said in its filing, for (yes) "advertising based on environmental conditions." It would provide another information layer, beyond quaint little GPS, that would target ads based not just on users' immediate locations, but on their immediate environments. So, the filing noted, detections of hot weather could serve up ads for air conditioners; or, inversely, winter coats. Or the phone sensors might detect, say, the distinctive sounds of an orchestra being tuned, and combine that information -- the user is at a concert -- with location data and local events data to figure out which concert the user is attending. And then serve ads (for nearby restaurants, orchestral CDs, local violin teachers) based on that intel.

Cool, no? And also totally creepy?

Well. This week, Google was granted its patent. The firm has officially patented background noise. (And also: cold. And also: warmth.)

There are huge privacy concerns here, obviously, one of them being that the ability to track devices' background noises would seem to imply the ability to track all their noises. And "it is important to respect the privacy of users," Google acknowledges in the patent, noting that monitor-tracking will be opt-out-able and that "a privacy policy" specifying which, and how, sensor-gathered information would be used "may be provided to the user." One wonders about the legality of the hypothetical operation in the 12 states that require everyone recorded to consent to that recording. The sound the phone picks up may just be an advertising signal for an algorithm to Google, but the law could see it differently.

