Aren't dashcams a form of a distributed surveillance system? Witnesses or victims of an accident often capture valuable evidence with dashcams of what happened
The comment above is talking about pedestrians and cyclists as well, who unfortunately have no option to have a "dashcam".
Bicycles can absolutely have dashcams, there are a few models on the market that attach to the rear because most collisions come from the rear. They have a built-in red light and can take continuous video and detect collisions.
Not strictly true; I, for one, don't hop on my bicycle without my helmet camera turned on.
if they have money they can buy a gopro; I've known many cyclists who list having the record of a potential accident as one of their reasons for buying and using a gopro.