Liberty Director Shami Chakrabarti and other speakers, including Julia O'Dwyer, mother of Richard O'Dwyer will meet in Sheffield later to show their support.
Mr O'Dwyer, a computer student at Sheffield Hallam University, is appealing extradition to the USA over claims he breached copyright with his website TV Shack. It offered links to pirated downloadable films and TV shows.
The Extradition Watch event will discuss Britain's extradition laws in the context of Mr O'Dwyer's case.
WATCH: Calendar's coverage of his extradition trial. Warning some flash photography.