The BBC has interviewed Andrew Lewman, executive director of the Tor Project.
His US-based team creates software that lets people visit websites anonymously and access otherwise hidden parts of the internet.
An article based on the interview can be found here, which focuses on Mr Lewman's belief that cyberspies in the US and UK are leaking his team information, frustrating their colleagues' efforts to compromise Tor's special browser software.
The following is a transcript of his wider-ranging conversation with BBC News Online's technology desk editor, Leo Kelion.
Some of the questions have been edited for the sake of clarity.