It was fitting that a memorial service held Saturday for computer freedom activist Aaron Swartz, who killed himself on January 11 as he faced hacking charges, was open to all.

In a spacious meeting room in the heart of New York's East Village neighbourhood, friends, fellow activists and supporters of 26-year-old Swartz gathered to recount fond memories mixed with angry calls for justice and a continuation of the fights that Swartz dedicated his life to.

Swartz's girlfriend, Taren Stinebrickner-Kauffman, was firm in her belief that Swartz's death had been caused by a prosecution system that had threatened him with up to 30 years in jail for hacking an online collection of academic journals linked to MIT with the intent of releasing millions of research papers on to the internet.

She said the prospect of a trial had dominated their life together and that prosecutors in the case should be held accountable for a tragedy that has shocked the tech community worldwide.

Stinebrickner-Kauffmann asked the packed crowd of several hundred inside the famed Cooper Union building's Great Hall - a scene of major civil rights and anti-slavery speeches in the past - to fight on for internet freedom and win justice for Swartz.

Her anger was matched by that of Roy Singham, a close collaborator with Swartz who founded the Freedom to Connect initiative.

In a fiery and emotional speech that earned a rousing standing ovation, Singham slammed the case against Swartz.

"This was not suicide. It was murder by intimidation, bullying and torment," he said.