Part of the plea deal that gets David Hicks out of Gitmo (and into an Australian jail to serve a 7 year sentence, some of which will be suspended) --
He also is barred from communicating with the media about his experiences, detention and capture for one year after sentencing and cannot receive profits from any publications detailing his experiences.
In the agreement, Hicks affirmed that he has never been illegally treated by anyone while in U.S. custody, from the time of his capture in Afghanistan in December 2001 through his time at Guantanamo.
So Hicks can't say anything that might (further) adversely impact PM John Howard's re-election bid later this year. Of course he could say something and challenge Howard's government ability to enforce the deal. Though it's understandable, if convenient for Howard, that he probably wants a quiet life for a while.