The book has been reviewed dozens of time in numerous different countries. Most have been interesting. A few have been eye-wateringly hostile (but revealing,too). You'll find most of them online. As a foretaste, here are some samples of the good, the OK and the ugly:

The good:

London Review of Books

http://www.lrb.co.uk/v30/n05/john-lanchester/riots-terrorism-etc

The Spectator

http://www.spectator.co.uk/books/476801/the-vile-behaviour-of-the-press.thtml

The Independent

http://www.independent.co.uk/arts-entertainment/books/reviews/flat-earth-news-by-nick-davies-782274.html

The OK:

The Observer

http://www.guardian.co.uk/books/2008/feb/03/society

 The Times

http://entertainment.timesonline.co.uk/tol/arts_and_entertainment/books/book_reviews/article3336139.ece

The ugly:

The Guardian

http://www.guardian.co.uk/books/2008/feb/09/pressandpublishing.society

The Sunday Telegraph

http://www.telegraph.co.uk/culture/books/non_fictionreviews/3671403/A-journalist-turns-on-his-profession.html