Camera placement has nothing to do with fear... It's going to be a rider decision based on their environment. In my case I have it mounted on the rear and it has absolutely nothing to do with fear.

I ride 30-50 miles a day, 6 days a week and it all mainly in medium to heavy city traffic. My guess, for my riding environment, and based on what I encounter daily is that 80% of my close calls are from rear approaching vehicles.

Cars driving in the bike lane, buzzing, ect. I rarely have instances with vehicles to the front and when I do its a left hook. A front mounted camera will probably not record the plate of a left hooking vehicle..

Don't assume people using a rear mounted camera are terrified of their own shadow........