Listening to all of this talk about reporters and their need to protect their sources, just makes me despair about the death of irony. The push for a shield law to prevent the government from compelling reporters to testify about sources of their stories is being lead by a group of idiots who are defending people who assisted in the violation of a "shield law" that does exist.
The most important classified information there is in the intelligence community, the information that everyone wants to protect and to discover is covered under the phrase: "sources and methods". The last things you want the "enemy" to know are "how you are gathering data, and the people providing that data". The "enemy" already knows what the data is, it's their data after all, but they don't know that you have it.
The government is required to protect its sources. There are laws in place to prosecute people who reveal those sources. There are people in prison for the remainder of their lives for revealing sources. As Culture Ghost
points out: there is no difference between what Aldrich Ames did, and what Karl Rove did. Both revealed the identity of sources and have damaged the ability of the United States to defend itself. Ames did it for money and Rove did it for revenge and power, but they both damaged the US intelligence community.
This isn't about politics; this is about national security. This isn't a dirty tricks investigation; this is an espionage investigation. If reporters want to have their "right" to protect sources considered, they might consider not becoming involved in a conspiracy to commit espionage against the United States. If they can't tell the difference, they might want to consider a career change.