One search on Google and I had the answer. In a word: evidence. An excerpt:
In Russia, everyone should have a camera on their dashboard. It’s better than keeping a lead pipe under your seat for protection (but you might still want that lead pipe).I've visited Russia dozens of times on work-related trips, but somehow I'd never run across this little facet. Perhaps its a very recent development, though, as the cost of dash-cams has come down a lot in the past few years (there are many under $100 on Amazon now). Knowing Russia reasonably well, I can confidently predict that there is a thriving market in fake dash-cams there :)
The conditions of Russian roads are perilous, with insane gridlock in cities and gigantic ditches, endless swamps and severe wintry emptiness on the backroads and highways. Then there are large, lawless areas you don’t just ride into, the police with a penchant for extortion and deeply frustrated drivers who want to smash your face.
Psychopaths are abundant on Russian roads. You best not cut anyone off or undertake some other type of maneuver that might inconvenience the 200-pound, six-foot-five brawling children you see on YouTube hopping out of their SUVs with their dukes up. They will go ballistic in a snap, drive in front of you, brake suddenly, block you off, jump out and run towards your vehicle. Next thing you start getting punches in your face because your didn’t roll up your windows, or getting pulled out of the car and beaten because you didn’t lock the doors.
These fights happen all the time and you can’t really press charges. Point to your broken nose or smashed windows all you want. The Russian courts don’t like verbal claims. They do, however, like to send people to jail for battery and property destruction if there’s definite video proof. That is why there’s a new, growing crop of dash-cam videos featuring would-be face-beaters backing away to the shouts of “You’re on camera, fucker! I’m calling the cops!”
Dash-cam footage is the only real way to substantiate your claims in the court of law. Forget witnesses. Hit and runs are very common and insurance companies notoriously specialize in denying claims. Two-way insurance coverage is very expensive and almost completely unavailable for vehicles over ten years old–the drivers can only get basic liability. Get into a minor or major accident and expect the other party to lie to the police or better yet, flee after rear-ending you. Since your insurance won’t pay unless the offender is found and sued, you’ll see dash-cam videos of post hit and run pursuits for plate numbers.