Shield Law?

After a 226 day serve Josh Wolf was released from prison on April 3rd. In 2006 he was put away for refusing to testify and release footage from a 2005 street demonstration in San Francisco at which a police officer and vehicle were injured. Many states, including California, have laws protecting journalists from having to reveal such information but in this case the federal government became involved, apparently overriding in protections provided by the state. Luckily there is proposed legislation out there to provide such protection at a federal level but the question that arises is who should be protected? Blogging gives anyone and everyone the capacity to be a journalist in their own eyes. My questions are: what constitutes a true journalist opposed to a casual blogger? and Who should be protected by shield legislation?