Eimear Cook, the ex-wife of golfer Colin Montgomerie, has told the court about a meeting she says she had with former News of the World editor Rebekah Brooks in 2004.
In Cook's recollection of the conversation, Brooks appears to refer to the practice of hacking voicemail messages.
Brooks and the other defendants deny all of the charges against them.
Cook told the court:
She said it was so easy to do and she couldn't believe that famous people who have all these advisors and they don't know they need to personalise or change their pin code to make them more secure.
The court heard that the meeting took place in September or October 2004 at the home of a mutual friend. The trial continues.
More top news
Another freezing, frosty and icy night ahead but this will be followed by a dry and sunny day for most tomorrow.
Phone hacking was "rife" at the Daily and Sunday Mirror newspapers and the People by mid-1999 at the latest, the High Court has heard.
Free banking may be a myth but it is one we are attached to - Barclays said they would like to charge for current accounts but could not.