It's being done to root out their confidential sources. This is the most blatant Bush attack on the freedom of the press yet. Details are here. Key graphs:
ABC News does not know how the government determined who we are calling, or whether our phone records were provided to the government as part of the recently-disclosed NSA collection of domestic phone calls.
Other sources have told us that phone calls and contacts by reporters for ABC News, along with the New York Times and the Washington Post, are being examined as part of a widespread CIA leak investigation.
You gotta hand it to Bush and his people. They really know their role models.
Like the old KGB.