Enhanced descriptions from Syndetics:

Meet Edinburgh Detective Inspector Liz Kavanaugh, head of the Innovative Crimes Investigation Unit, otherwise known as the Rule 34 Squad. They monitor the Internet for potential criminal activity, analyzing trends in the extreme fringes of explicit content. And occasionally, even more disturbing patterns arise...

Three ex-cons have been murdered in Germany, Italy, and Scotland. The only things they had in common were arrests for spamming--and a taste for unorthodox entertainment. As the first officer on the scene of the most recent death, Liz finds herself sucked into an international investigation that isn't so much asking who the killer is, but what--and if she doesn't find the answer soon, the homicides could go viral.

Reviews provided by Syndetics

Library Journal Review

Called to the scene of a gruesome and bizarre murder, Detective Inspector Liz Kavanaugh, head of Edinburgh's Innovative Crime Investigation Unit (the "Rule 34 Squad"), discovers a rash of criminal activities that span the globe and seem to be linked to a particular kind of Internet research involving sophisticated programs that target illicit cyberactivities. Faced with pressure from her department to curtail her efforts, Kavanaugh must weigh the importance of her career against the need to do what is right, regardless of the cost. VERDICT Stross (Singularity Sky) draws on tomorrow's technologies to create a story that features intriguingly offbeat characters and a labyrinthine puzzle of a plot. Fans of modern cyber-fi literature as well as technological thrillers should enjoy this thinking person's sf adventure. (c) Copyright 2011. Library Journals LLC, a wholly owned subsidiary of Media Source, Inc. No redistribution permitted.

Publishers Weekly Review

Hugo winner Stross blends plausible near-future SF and crime in this brisk sequel to 2007's Halting State. In the mid-2020s, the police monitor the Internet full-time to prevent crime. In Edinburgh, this job falls to DI Liz Kavanaugh's Rule 34 Squad (whose name refers to the Internet truism that "if it exists, there's porn about it"). Kavanaugh views the position as a demotion, but she has a chance to get her once-promising career back on track when she is called to supervise the inquiry into the death of drug dealer Michael Blair, who was found dead on his bathroom floor, decked out in s&m garb. Her investigations are interwoven with the stories of an unlikely diplomat and a criminal known as the Toymaker. Each section builds on the others, making the whole more than the sum of its parts. (July) (c) Copyright PWxyz, LLC. All rights reserved.

Booklist Review

Stross' latest novel is laid in the same near-future Edinburgh as Halting State (2007) but is not directly related. Detective Inspector Liz Kavanaugh is head of the Innovative Crime Investigation Unit. It monitors the Internet, trying to distinguish between people indulging in harmless, if bizarre, fantasies and those committing crimes. But sometimes, as now, something more disturbing surfaces. Three ex-cons have been murdered in three separate countries of the European Union. What they had in common were arrests for spamming and a taste for extremely odd erotica. But as she investigates the Scottish victim, Liz begins to suspect that the killer may not be a who, but a what that may not be stoppable in real time. Stross' characters are a convincing assortment of the residents of present (and likely future) Edinburgh. His language is a bit tech-heavy, but so is the story setting, so the style adds verisimilitude. The plot, with its all-too-likely extrapolation of cybercrime, is both a good read and a warning. In fact, Stross noted in one of his blog entries that he had to keep rewriting the book because virtual reality kept catching up with it. Rule 34 should please Stross fans, cybernuts, and thriller fans.--Murray, Fried. Copyright 2010 Booklist