The first is because she is a prominent person and has in recent times attracted strong public criticism and hostility. This might be said to cause a risk that jurors at her eventual trial could be prejudiced against her.
The second reason is that she and others speaking on her behalf have accused the police and the Crown Prosecution Service of acting unfairly in launching the prosecution. Her husband Charlie, for example, has accused the CPS of conducting a witch-hunt, and the Daily Telegraph is reporting that her legal team are considering a legal challenge on the grounds that the prosecutor was not impartial.
Let’s look at the first issue first. It is not a new problem, or even a particularly rare one. Down the years many well-known people have been in the dock, from Jonathan Aitken, Jeffrey Archer, Harry Redknapp and the Maxwell brothers to David Norris and Gary Dobson in the Stephen Lawrence case and the gangster Kenneth Noye. Though some had been the subjects of very hostile publicity they were tried none the less. It is hard to see how it could be otherwise: we could not have an arrangement under which we simply never prosecuted unpopular people – that would be like telling them they could break as many laws as they liked.
What we do instead is try to protect them from prejudice. The Contempt of Court Act aims to curtail reporting about cases from the moment things get serious, so that by the time the jury gets to hear the evidence things have calmed down. (That is the idea, at least.)
In the case of Rebekah Brooks, then, it is not an argument to say that she can’t be tried because people have written nasty things about her. We would expect her to rely, like anyone else would have to, on the protection of the contempt law. She has chosen not to do this. Instead of allowing that period of silence to begin in the hope that with time any prejudice against her would fade, she and those acting for her have been vigorously drawing attention to her case with their series of well-publicised complaints.
It is an unusual tactic, not least because it opens the legal door to new criticisms of her that would normally, at this stage, risk breaching the contempt law: she could hardly complain now, for example, if others accused her of arrogance in her treatment of the prosecuting authority, to which most citizens submit without question.
She might also be accused of hypocrisy. What she is doing could be described as posturing, for one thing. And for another, when she edited tabloids they never seemed to care much for the rights of people accused of crime; on the contrary they were quick to condemn and demand harsh punishment. Her concern in her own case could be described as a bit rich.
So if there is really a risk of prejudicing future jurors here, Brooks and her advisers might actually be increasing it.
And what might their tactic achieve? Imagine that the CPS caved in now and dropped the charges, where would that leave Brooks? At liberty, for sure, but not in any way vindicated. She and her associates insist that the charges are trumped up and there is no real case to answer. If that is the case, surely she would prefer to clear her name.
It is very unlikely that the CPS will cave in, so in due course the evidence in this case will be a matter for a jury, and here Brooks would seem to have at least as many advantages as disadvantages. She will be tried by 12 of those ordinary members of the British public with whom, in her evidence to the Leveson inquiry, she professed such a strong affinity. Some of them, no doubt, will actually be Sun readers.
She also still has a lot of friends in the press and, as Roy Greenslade has shown, is capable of securing the kind of coverage of her case that she wants. And she is also a very wealthy woman (her pay-off from News International alone is reported to have been £1.7m ), and so she can afford some of the country’s most expensive lawyers.
Far from having the odds stacked against her, in fact, I would say Rebekah Brooks will have advantages going into court that most of us could never dream of. So why doesn’t she shut up and allow the law to run its course?
Brian Cathcart teaches journalism at Kingston University London and tweets at @BrianCathcart