I have had attempts of this a few times, recently on Broadway in the Bronx a car with about 4 people in was visible in my mirrors for a mile or so, then came along side when I got to t he 30 mph mark, it pulled sharply in front and hit the brakes, luckily not only do I have a dash cam, my truck also has a automatic braking system such as we often see in the Volvo and Scania videos on you tube. Several attempt later we pulled up at some lights and he was watching me in his mirror, I pointed to the dash cam and shouted, “Should I call the cops ?” He gave me the middle finger and sped off… Which is just as well, because after 3 years of owning the dash cam I still have no idea how to upload the videos ? 