When Laura Poitras flew to Hong Kong to meet Edward Snowden, she brought a copy of Cory Doctorow’s novel Homeland. It wasn’t an innocent gift. After communicating via technical encryption for months, the pair had decided that a more analog method of encoding their discussions might prove necessary. They settled upon a tried and tested method: a book cipher.

Anyone who has read Doctorow’s Homeland will understand immediately why Poitras settled upon it. Not only does it — like Doctorow’s other novels — break down for the lay public in accessible prose the range of surveillance practices and technical capabilities at the US government’s disposal — precisely the kind of conversation Snowden, Poitras, and Glenn Greenwald would be having over the next few days — but the book’s central plot is about a young and technically gifted idealist who goes public with secret evidence that incriminates the national security state’s repressive practices.

Doctorow follows in a long tradition of novelists who have examined the implications of mass surveillance, but his message is more empowering than many writing on technology today. Perhaps because he is both an activist (he ran the European wing of the Electronic Frontier Foundation and set up the UK Open Rights Group) and an author, his novels celebrate the idea that individuals can bring about change and use technology to overcome the surveillance state.