City buses across America increasingly have hidden microphones that track and record the conversations that take place on them. It's easy to see the reasoning behind this: once it's acceptable to video-record everything and everyone on a bus because some crime, somewhere was thus thwarted, then why not add audio? If all you need to justify an intrusion into privacy is to show that some bad thing, somewhere, can be so prevented, then why not? After all, "If you've got nothing to hide..."
According to the product pamphlet for the RoadRecorder 7000 system made by SafetyVision (.pdf), “Remote connectivity to the RoadRecorder 7000 NVR can be established via the Gigabit Ethernet port or the built-in 3G modem. A robust software ecosystem including LiveTrax vehicle tracking and video streaming service combined with SafetyNet central management system allows authorized users to check health status, create custom alerts, track vehicles, automate event downloads and much more.”
The systems use cables or WiFi to pair audio conversations with camera images in order to produce synchronous recordings. Audio and video can be monitored in real-time, but are also stored onboard in blackbox-like devices, generally for 30 days, for later retrieval. Four to six cameras with mics are generally installed throughout a bus, including one near the driver and one on the exterior of the bus.
Cities that have installed the systems or have taken steps to procure them include San Francisco, California; Eugene, Oregon; Traverse City, Michigan; Columbus, Ohio; Baltimore Maryland; Hartford, Connecticut; and Athens, Georgia.
There are lots more exciting possibilities opened up here. For example, our phones and laptops could continuously stream all the audio from our immediate surroundings when we're in public, even when we're not actively using them. No one would listen to them in real-time (or, at least, no one would be authorized to do this), unless they were a cop or someone in government. But when a crime was committed, imagine how useful it would be if all the phones in the vicinity could be tapped for a record of the event!
Why not? If you've got nothing to hide?
This is the NSA's argument, by the way. They're recording all of the Internet and voice traffic in the USA, but they only plan on examining it after the fact, to find criminals who do bad, bad things. Once you accept that logic, there's no reason that they shouldn't put prisoner-tracking ankle-cuffs on all of us (mobile phones are only slightly less invasive than these, anyway, in the current legislative regime), start using lawful interception backdoors to watch us through the webcams in our consoles and computers, and so on.
It's also UK Home Secretary Theresa May's argument in favour of her "Snooper's Charter" -- the communications act she's pushing, which will give law enforcement the power to order service providers to retain any data, and give government and law enforcement access to it.