Prosecutors have sought phone records from reporters before, but the seizure of records from such a wide array of AP offices, including general AP switchboards numbers and an office-wide shared fax line, is unusual.

WSJ: Gov't probe obtains wide swath of AP phone records

The exact number of journalists who used the phone lines during that period is unknown, but more than a hundred journalists work in the offices where phone records were targeted, on a wide array of stories about government and other matters.

WSJ: Gov't probe obtains wide swath of AP phone records