When I worked in Russia, I asked the same (they were doing it 10 years ago) - it was to protect against fraudulent insurance claims and scams... quite a lot of people strapped an old camcorder to the dash and ran a tape all the time they were driving.... people used to step out on purpose and smash a wing mirror, then throw themselves on the floor surrounded by lots of 'witnesses' - they would then harass the driver to pay cash to keep it quiet.