An inquiry launched in the wake of the phone-hacking scandal has heard details suggesting that the illegal practice was widespread.
Notebooks belonging to private detective Glenn Mulcaire suggest he hacked phones for the Sun, the Daily Mirror and the News of the World.
Some 28 NoW employees were named in the notebooks, the inquiry heard.
Earlier, Lord Leveson warned newspapers not to victimise inquiry witnesses who speak out against press intrusion.
But he added he had "absolutely no wish to stifle freedom of speech and expression".
Counsel to the inquiry, Robert Jay QC, gave details of notebooks belonging to Mulcaire, who was jailed with the News of the World's former royal editor Clive Goodman in 2007 after admitting intercepting messages on royal phones.
Mulcaire wrote first names in the top left-hand corner of his notes recording voicemails he illegally intercepted, the hearing learned.
Some of these corresponded to NoW employees, one of whom - referred to only as "A" - apparently made 1,453 separate requests for information.
But he also wrote "The Sun" and a name relating to the Daily Mirror in his notebooks, the inquiry was told....read more