New research finds the presence of security cameras negates the famous bystander effect and encourages people to help those in need.

Many of us are of two minds regarding security cameras: Were concerned about the loss in privacy, even as we appreciate the role they play in reducing crime.
Newly published research suggests their presence also has another, distinctly positive effect. They apparently prompt people who are part of a crowd to engage in helpful behavior, thus weakening the famous bystander effect.
The camera is able to increase intervention when people are otherwise least likely to help: When other bystanders are present, reports a research team led by psychologist Marco van Bommel of VU University, Amsterdam. Their research suggests that, if they believe their heroic or helpful action will be caught on camera, people who would otherwise remain passive have a strong incentive to intervene to be seen.