An FBI investigation preceded Dmitry Sklyarov's arrest
A Russian computer programmer is still being held in the United States, despite a change of heart by the company that wanted him arrested.
He was arrested in the US after he addressed the Defcon 9 internet security convention in Las Vegas.
Adobe put out a statement calling for Mr Sklyarov's release after company representatives met the EFF, a US free speech and electronic privacy pressure group.
Controversial legislation
"We strongly support the Digital Millennium Copyright Act and the enforcement of copyright protection of digital content," said Colleen Pouliot, Adobe's Senior Vice President and General Counsel.
Adobe's climbdown also follows a series of public protests in support of Mr Sklyarov and calls to boycott its software, which includes the popular image editing tool Adobe Photoshop.
The United States' Digital Millennium Copyright Act (DMCA) is a controversial piece of legislation providing for stiff penalties against the developers of software tools used to circumvent copyright protection.
Its critics say that it targets the developers of tools that also have legitimate uses, instead of going after those who break copyright law.
'Top US problem'
Mr Sklyarov's software allows users of Adobe's program to move and make copies of electronic documents.
Adobe objects to this because when electronic books are sold, there are typically restrictions on the number of copies that can be made.
Mr Skylarov's arrest came in the same week that US Attorney General John Ashcroft described computer security as one of the US's top problems and announced the appointment of extra prosecutors.
"There are many people of poor and evil motivations who are seeking to disrupt business and government and exploit any vulnerabilities in the digital universe."
Letting computer crimes go unpunished "impairs the ability of the United States of America to remain in its position of priority in leading the world in the digital age", he said.
Five-year penalty
The case against Mr Sklyarov is the first criminal action under the DMCA.
If the US Government ignores Adobe's climbdown and goes ahead with the prosecution, he faces a maximum of five years in prison and a fine of $500,000.
Mr Sklyarov's employer, Russian software company Elcomsoft, said after his arrest that Adobe should fix security problems in its eBook Reader software instead of pursuing him.
No date has yet been set for his next court appearance.
Mr Sklyarov's case has parallels with continuing legal wrangling in the US over DeCSS, a piece of software which unlocks encoded DVDs, and over the publication of details of how to break SDMI, a planned protection scheme for digital music recordings.