I certainly wouldn't call these videos funny in any way shape or form.
In the first one, it's a miracle that the rider got up and was able to walk around.
The second one is a classic incident of a car driver not paying attention and cutting in front of the rider - more riders are seriously injured or killed every year from this sort of accident.
In the third video, the rider was obviously at fault, given how slowly the car was making its turn. The rider should have seen the car and been able to stop.
The fourth one is hard to say who is at fault, as there are no visible traffic signals to indicate right of way. It also looks like the injuries sustained by the rider and passenger were more severe than in the other videos.