This essay by Kenan Malik on self-censorship, arising from the ghastly situation with The Jewel of Medina, is well worth reading.
The Jewel of Medina, by American author Sherry Jones, is, as Malik puts it, "a romantic tale about Aisha, the Prophet Muhammad's youngest wife." It was originally bought by a major trade publisher in the US, Random House, which subsequently pulled out for fear of violent reactions from Muslim radicals. This was after the publisher received advice - from an academic, Denise Spellberg, who was asked to provide an endorsement - that it was offensive to Muslims. (Note to self: be very careful who you ask for endorsements.) Subsequently, The Jewel of Medina sold to a smaller publisher in the UK, Gibson Square. Alarmingly, Gibson Square's offices were firebombed as it was about to issue the book in late 2008. Nonetheless, the book is available and apparently doing well.
Ironically, it may not have been such a magnet for violence if it had been published routinely by Random House with no fuss. As a further irony, although the book is apparently something of a bodice-ripper - romantic and ahistorical - all reports suggest that it is not hostile to Aisha, Muhammad, or Islam.
While we rightly fear infringement of our freedom of speech by the might of the state, there are other ways that our thoughts and free expression can be silenced, such as by intimidation, cowardice, toleration of the intolerant, extreme unwillingness to give offence, and a lukewarm social ethos in which free speech is given low priority.