Wikipedia's general definition of digital journalism.

What used to be information and savings delivered to the doorstep of a home has now become an array of "digital doorsteps" otherwise known as email inboxes, social networks and mobile phones.

Traditional definitions of privacy fit somewhat uneasily into social media. Privacy is about intrusion rather than secrecy and the question is whether you have a reasonable expectation that something is private, rather than whether you have done or said something in public. These concepts are not easy to apply to social networking sites where the point of the exercise is to share information with others.

The use of Facebook is not only the opportunity to search for new stories, but it also represents a new ethical issue for journalists. What are the limits in using personal information published online? 

In the hours following the Virginia Tech shootings, reporters were quick to sign up for Facebook accounts to find people touched by the campus shootings. This digital door stepping provoked a wave of resentment from students, as if the reporters were eavesdropping on conversations between friends.