Rule 34 is a near-future crime novel, set in an independent Scotland as the future of the nation is under debate and artificial intelligence is taken for granted. Its a sequel of sorts to Halting State, set in the same universe but not within the same gaming subculture.
As we move between the narrating characters it becomes clear that there are an awful lot of coincidences and people turning up dead in surprising ways. Stross controls how the reader receives information allowing a complex situation to be developed and then how all the pieces fall into place at the end.
The detective work is handled well: avoiding the trope of a lone detective with a large team working together, using an online sharing space which all police on the case can access dynamically. I did love that they still organised face to face meetings too, acknowledging the value of that for human communications.
Beyond the police work, the science fiction element is very well done. Completely believable in these days of Sharepoint, Google and Google Glasses and appropriately taken for granted by the protagonists who just consider it to be how the world works.