Also, if paid news sources are automatically suspect, shouldn't expert witnesses who are paid for court testimony be equally suspect? Shouldn't the police be barred from paying informants for the same reason? (Well, yes. I inadvertently undermine my own case. Please ignore!)
The taboo against paying sources—and the opprobrium dumped on the news outlets that pay—has more to do with maintaining the status quo for established, old-guard news institutions than it does with protecting journalistic truth. Established news institutions depend on their high status, and the high status of their audiences, to lure and lock up sources. (If you've ever worked a story at the same time and in the same place as the New York Times, you know what I mean.) In practice, old-guard institutions "pay" much more for their stories than the outlets that pay sources directly. The main difference is that the old guard's payments go to their far-flung correspondents and to the institution's stockholders, not to sources. The longer the old-guarders can keep the public convinced that it's more ethical to give the old-guarders information for nothing, the better off the old-guarders will be.
Whether a source is paid or not, the information from that source must be vetted, and as one who has repeatedly been lied to by unpaid sources, I don't see why paid sources should be considered less credible than unpaid ones. In fact, you could make the argument that paying a source increases credibility, because if he gives you lies in return for payment, at least you have the legal leverage to sue him for fraud. If an unpaid source lies to you, what can you do? Pound sand?
Authority has been displaced as the primary arbiter of truth by confirmation, thanks to the Web and, to a lesser degree, the proliferation of cable news. It no longer matters what Secretary of State Hillary Clinton says if, to pose a hypothetical, she is contradicted by a wad of diplomatic cables sold to a news outlet that confirms their essential truth. Confirmation is the new, great journalistic leveler.
As a creature of the old guard, I'm made itchy by the prospect of sources nickel-and-diming me for information. But the sanctimony of the ethicists gives me full-body chiggers.
Scratch my itch with email to firstname.lastname@example.org or pour calamine lotion on my Twitter feed. (Email may be quoted by name in "The Fray," Slate's readers' forum; in a future article; or elsewhere unless the writer stipulates otherwise. Permanent disclosure: Slate is owned by the Washington Post Co.)