Jurors hearing the case of former News International chief executive Rebekah Brooks and ex-spin doctor Andy Coulson were told today that "British justice is on trial".
Mr Justice Saunders gave the panel of nine women and three men at the Old Bailey detailed instructions after they were sworn in today, warning them to consider the case only on the evidence and arguments presented in court.
He made particular reference to the cover of the current edition of Private Eye, telling them to ignore what he called a joke "in especially bad taste".
The judge told them: "I'm going to give you some extremely important directions. They are always important, but they could not be more important than they are in this particular case. In this case in a way not only are the defendants on trial, but British justice is on trial."
He added: "It is absolutely vital that you decide this case solely on the evidence and the arguments that you hear in court."
The judge warned them that there had been an unprecedented amount of publicity previously about the case, some of which was "offensive and demeaning" to some of the defendants.
He then showed them a copy of Private Eye, saying: "Unfortunately Private Eye has seen fit today to put out their November edition. You will undoubtedly see it on the newstands, so I can show it to you.
"It bears a picture of Rebekah Brooks on the cover. It's meant to be satire. You ignore it. It has no serious input and it is not relevant to your considerations.
"It is one of those things that you will have to ignore - a joke which in the circumstances of today is a joke in especially bad taste."
Jurors were warned not to discuss the case with anyone outside their 12, including on social media such as Twitter or Facebook, and were warned of previous cases where jurors were jailed for contempt of court for breaching instructions about discussing the case online.
The judge told the jury: "At the end of the day I hope and expect that the issues that you have to consider will boil down to relatively simple issues but there is a very large amount of information which needs to be presented to you in the most manageable form."
He said an "enormous" amount of work had already been done, but there was still more to be done so the trial will not open until 2pm tomorrow.
Brooks, 45, of Churchill, Oxfordshire, and Coulson, 45, from Preston in Kent, are both accused of conspiracy to intercept communications in the course of their transmission.
They allegedly conspired with former News of the World (NotW) head of news Ian Edmondson, 44, from Raynes Park, south west London, the tabloid's ex-managing editor Stuart Kuttner, 73, from Woodford Green, Essex, and others to illegally access voicemails between October 3 2000 and August 9 2006.
Ex-NotW and Sun editor Brooks is also charged with two counts of conspiring with others to commit misconduct in public office - one between January 1 2004 and January 31 2012 and the other between February 9 2006 and October 16 2008 - linked to alleged inappropriate payments to public officials.
She faces another two allegations of conspiracy to pervert the course of justice - one with her former personal assistant Cheryl Carter, 49, from Chelmsford in Essex, between July 6 and 9 2011.
It is alleged that they conspired to remove seven boxes of material from the News International archive.
The second count alleges that Brooks, her husband Charles Brooks and former head of security at News International Mark Hanna conspired together and with others between July 15 and July 19 2011 to pervert the course of justice.
It is claimed that they tried to conceal documents, computers and other electronic equipment from police officers who were investigating allegations of phone hacking and corruption of public officials in relation to the News of the World and The Sun newspapers.
Former No 10 spin doctor and ex-NotW editor Coulson is also facing two allegations that he conspired with the tabloid's former royal editor Clive Goodman, 56, from Addlestone in Surrey, and persons unknown to commit misconduct in public office - one between August 31 2002 and January 31 2003, and the other between January 31 and June 3 2005.
All eight defendants are on bail and the case was adjourned to tomorrow at the Old Bailey.
Mr Justice Saunders told the jury that actors and politicians may write blogs and tweets expressing their views about subjects that fall into their area of expertise but also on "matters on which they know very little".
He told the panel: " I very much hope that they will not do so during the trial and they may well be breaking the law if they do do so" and added: "They will be uninformed views, do not read them."