This video accurately portrays the bystander effect. This also shows the diffusion of responsibility; the more people in a group, the less likely someone will help because they expect someone else will.
This is an example of the bystander effect. The people walking in this video have several reasons not to help them man lying on the ground. The reasons range from giving excuses for his behavior ("he's drunk"), which to them is not a really important reason to help him, to putting the responsibility on others ("I'm sure someone else will handle it").