Probably due to avoid Copyright issues the covers of various media shown in the movie are different than in real life. While the cover of "Confession of a heiress" is similar to the real one, except for Paris' dress on the cover of the book, the cover of "1 Night in Paris" is entirely different than the one in real life.
Paris Hilton's private information and photographs were not obtained from her stolen or lost cellphone as implied in this movie. Her cellphone account was broken in to by a computer hacker over the Internet.