In the wake of the recent meteor strike in Russia, the prevalence of dash cam video and stills has been brought to the front of discussions. The vast availability of vehicles with these devices--most ranging from VGA to 1080P resolution--makes for a great source of scientific content for analyzing such an event (see image below courtesy of the BBC).
These cameras, most with MicroSD storage for the DVR, record 30 to 60 minutes of video and then re-record the loop. The goal is to help document accidents and determine fault of others versus the fault of the driver.
Ubiquitous vehicular (and ground based) video has serious implications for privacy (as well as distracting drivers) but the ability to record unexpected natural phenomena such as tsunamis, tornadoes, and meteor strikes makes for some remarkable videos. These video recordings also make it possible to reconstruct crimes in ways that we never imagined a few years ago.
I thought a part of the reason for these cameras was to protect the drivers from corruption? I do think that they are a great idea but it is a two edged sword: could be used to help or prosecute the driver.. Anyway, as long as there is no viewing screen to distract the driver I think they are a great way to document the unexpected.