It happens, people are selfish sometimes. One day, I forgot my road helmet and had to wear my mtb helmet. It has a light attached to the top and I didn't take it off because I was out of time from looking for the road helmet.
About an hour into our group, this car with two men in it is cursing us all out as they pass us. When they got to me, I turned my head and as I was pointing to the helmet light, said "hi, wave for the camera"..... they sped off.
Now, I wear my GoPro on all rides and a few times, it was proven to provide some good info about the rides.