Apple failed to meet First Amendment requirements in its much-publicized case against journalists in the US.
The Electronic Frontier Foundation (EFF) last week won the right to have hitherto secret court documents filed by the computer company unsealed.
These reveal that Apple issued subpoenas forcing two reporters' to disclose anonymous sources without first conducting a thorough investigation inside the company.
EFF calls this a "crucial issue in the case".
This is because the First Amendment and the California Constitution require Apple to have exhausted all other alternatives open to it before trying to subpoena journalists.
Journalists worldwide have seen the case as a test which if successful for Apple could make it impossible to engage in investigative reporting.
Liberty demands duty of care
The unsealed documents show Apple never took depositions from employees, never issued subpoenas (other than to the journalists), and never asked for: "Signed declarations or information under oath from its own employees", the EFF said.
The EFF and co-counsels Thomas Moore III and Richard Wiebe, is representing journalists from AppleInsider.com and PowerPage.org.
Both sites printed articles about a secret Apple product, code-named "Asteroid". This was described as a Firewire audio interface for GarageBand.
Apple took legal action claiming violation of trade secret laws. In December, the company sued several unknown parties, known as "John Does," who allegedly leaked information about the product.
What is a 'trade secret'?
Crucially, Apple also claimed its internal investigation to be a trade secret, demanding it be sealed from the defendants.
They show that the only computer forensics conducted by Apple were a search of Apple's email servers and a rudimentary examination of a single file server.
Apple failed to examine employees' individual work computers, hard drives, telephone records, photocopiers, "or otherwise investigate the possibility that information about Asteroid was transmitted by means other than email", the EFF said.
Apple also failed to obtain sworn statements from employees who had access to the leaked information.
Press freedoms matter
"The First Amendment requires that compelled disclosure from journalists be a last resort," said EFF staff attorney Kurt Opsahl. "Apple must first investigate its own house before seeking to disturb the freedom of the press."
A California Superior Court ruled earlier this year that the subpoenas could be issued, both to the journalists' email providers as well as the publishers of the site. The journalists appealed the ruling, so the court ordered Apple to prove why the appeal shouldn't be granted.
No date for the Appeal Court hearing has been set.