JK Rowling has told the Leveson Inquiry that she has had to take action against newspapers about 50 times over breaches of privacy and misreporting.
The author said journalists "drove her out" of the home she bought in 1997 with the advance from the first of her seven Harry Potter books.
She told the inquiry into press standards she felt like a "sitting duck" after a photograph was published of the house number and street name, and it became "untenable" to remain there.
Rowling described her anger when she found a note that a reporter had slipped inside the bag of her elder daughter when she was in her first year at primary school.
She recalled: "I unzipped her schoolbag in the evening, and among the usual letters from school and the debris that every child generates, I found an envelope and a letter addressed to me from a journalist. The letter said that he intended to ask a mother at the school to put this in my daughter's bag.
"I can only say that I felt such a sense of invasion. It is very difficult to say how angry I felt that my five-year-old daughter's school was no longer a place of complete security from journalists."
Earlier in the day, Sienna Miller told the inquiry she had accused her family and friends of selling stories to the media after journalists obtained intimate information about her by hacking her phone. The actress described how she felt "terrible" for even considering that those closest to her could betray her in this way.
And former Formula 1 boss Max Mosley recounted to the inquiry how he took the News of the World to court for its "sick Nazi orgy" story about him because he was so keen to "demonstrate they were liars".
He proceeded with the High Court action despite being warned it would cost him dearly and bring his private information back into the public domain, he said.
The inquiry heard that future witnesses will include former News of the World and Daily Mirror editor Piers Morgan and ex-News of the World chief reporter Neville Thurlbeck.