Everyone has an obligation to help law enforcement, and under certain circumstances, that entails that one gives up some of their privacy (personal information, social media, etc.) to help them with a problem or case that they need to solve.

There is no need for privacy or concern about hackers if everyone does what they are supposed to do and has nothing to hide.

In the case of Trayvon Martin, in which the eyewitness accounts were conflicting with one another, video evidence of the altercation could have made it easier for the jury to make a decision.

Surveillance of social media and Internet activity can prevent shootings and bombings from occurring if certain keywords and searches were red flagged, potentially protecting the lives of many people.