I've been running a helmet cam since 2014, but I haven't had any interactions with cars worth sharing with the police. There have been a few encounters with "urban campers" where the video has helped...not with apprehension, but with the clearing of the homeless encampment where the incidents occurred...physical threats, uncontained fires, impassable debris and corporeal roadblocks.

When drivers become verbally aggressive I point at my helmet cam and that usually stops them. One summer day, years before my helmet cam before smart phones, but when flip-phones started coming with cameras I had a driver stop after passing me on a side street. He had honked, and I honked back with my Airzound air horn. He screeched to a stop, got out of his car and started walking back to me in an aggressive manner shouting threats. A woman got out of the passenger side and begged him to get back in the car. I grabbed my phone and held it up in front of me as if it had a camera. He saw it, turned around and left.

I like to think having a helmet cam can stop aggressive situations from progressing, but there's always the possibility that the aggressors will want to destroy any evidence of their behavior and try to take the camera at which point they would be free to wreak havoc.