One Hand Clapping makes a fair point:
Any reporter who works government beats will tell you that 95-percent-plus of the "confidential" information leaked to them by people of either party has no purpose other than to damage the opposition. Why reporters let themselves be used as pawns in political chess quite escapes me.
He answers his own question, but he got me thinking about a book i read years ago: Edward J. Epstein's, Between Fact and Fiction: The Problem of Journalism (New York: Vintage Books, 1975)
The problem of journalism in America proceeds from a simple but inescapable bind: journalists are rarely, if ever, in a position to establish the truth about an issue for themselves, and they are, therefore, almost entirely dependent on self-interested 'sources' for versions of reality that they report. p. 3
Indeed, given the voluntary nature of the relationship between a reporter and his source, a continued flow of information can only be assured if the journalist's stories promise to serve the interests of the witness. p. 7
Despite the heroic public claims of the news media, daily journalism is largely concerned with finding and retaining profitable sources of pre-packaged stories. p. 9
What is called 'investigative journalism is merely the development of sources within the counter-elite or other dissidents in the government, while 'stenographic reporting' refers to the development of sources among official spokesmen for the government. There is no difference in the basic method of reporting. p. 10
By concealing the machinations and politics behind a leak, journalists suppress part of the truth surrounding a story. Thus, the means by which the medical records of Senator Thomas Eagleton were acquired and passed on to the Knight newspapers (which won the 1973 Pulitizer Prize for disclosing information contained in these records) seems no less important than the senator's medical history itself, especially since copies of the illegally obtained records were later found in the White House safe of John Ehrlichman. p. 17
Epstein doesn't have a blog, but he does have a very interesting website.