There is a time-hallowed code of honour in Fleet Street, the former centre of Britain's now scattered national newspaper industry: 'dog doesn't eat dog'.
Fortunately (for fans of reality shows featuring fantasy characters) this has been ignored by Sir David and Sir Frederick Barclay - twin brotherly knights of Her Majesty's realm, gothic entrepreneurs who inhabit a fortified island off the coast of France, and current owners of Telegraph Newspapers.
On Tuesday the secretive siblings laid criminal charges against rival newspaper The Times, its editor Robert Thompson and media editor Dan Sabbagh.
It seems the Barclays are irked by an article published last year by The Times about their more interesting business activities. Although legal remedy is open to them in the UK courts - which usually take a fairly draconian view of libel - the brothers have opted to retaliate through the French legal system where defamation is a criminal offence.
The brothers, to whom a few billion pounds one way or the other is of little account, demonstrated their contempt for the British taxpayer by wasting the time of the nation's police force to serve their proceedings. A detective from Scotland Yard, no less, delivered the legal documents in person to The Times and the named defendants.
The Times, which circulates around 600,000 copies daily in the UK, also sells a meagre 3,000 in France, thereby enabling the Barclays to exploit the French legal system Explains a lawyer: "The UK libel laws are as strong as you'll get anywhere, but in France it's a penal code. In that sense it is more of a deterrent."
Says editor Thompson: "If newspaper proprietors such as the Barclay brothers think it is appropriate to launch this extraordinary case, what signal does it send to more vexatious litigants who would seek to silence the media?
"They were quite entitled to bring a case under British libel laws, which are among the toughest in the world, but have chosen, instead, this unusual course of criminal action which sets an unfortunate precedent for all media, and not just British newspapers.
"This really is a remarkable breach of tradition and made even more remarkable by the fact that the case has been brought by newspaper owners. Whatever his failings, it is difficult to imagine Conrad Black [the Telegraph's former owner] pursuing a criminal case of this kind in the French courts."
A hearing has been scheduled for 23 June when a date for trial will be set. The UK media industry is bracing itself for what could become Europe's top reality show.
Data sourced from MediaGuardian.co.uk; additional content by WARC staff