Last week, the Court of Appeal delivered a ruling in a case between warring multi-millionaire spouses Lisa and Vivian Imerman.
After the couple split up in 2008, Lisa's brother, Robert Tchenguiz, feared that Vivian would conceal his assets, so he accessed a server in an office which they previously shared. He then copied (with the help of the other defendants) between 250,000 and 2.5m pages of his brother-in-law's documents and handed these over to his sister's lawyers.
Vivian said Robert invaded his right to privacy and argued that, since the documents were acquired unlawfully, Lisa shouldn't be able to use them in her bid to win ancillary relief.
Going into the case, Lisa's lawyers cited the so-called "Hildebrand rules", which permit a party to take and copy their spouse's documents so long as they do not use force or retain the originals. They argued refusal to apply the rules in this case would rob women of protection previously afforded to them. "Wives have until now been allowed to produce an ace from their sleeve: a document proving the husband had lied about his finances was admissible even if improperly obtained," they said.
The Court of Appeal disagreed, however. Lord Neuberger MR called it "an extreme case of wrongful access to confidential material".
They said Vivian's right to privacy under article 8 of the European Convention on Human Rights had been violated, since he had a reasonable expectation of privacy in his email correspondence and other documents stored on the server. Just because Robert Tchenguiz owned the server and had physical access to it did not alter that.
"Confidentiality is not dependent on locks and keys or their electronic equivalent," said Lord Neuberger.