Ramez Naam's debut novel Nexus is a superbly plotted high-tension technothriller about a War-on-Drugs-style crackdown on brain/computer interfaces. Kaden and his friends are Bay Area grad students who've hacked Nexus 3, a recreational party drug that nano-infests its users brains and makes them weakly telepathic while they dance the night away. What Kaden and his fellow bio-hackers do is build a Turing-complete virtual machine on top of this platform, port a lightweight version of GNU/Linux (or fictional analog) to it, and start running software on their own minds, arranging for strongly telepathic, hive-mind-style linkups.
This turns out to be a completely prohibited activity in the USA, where enforcement of a convention against posthuman and transhuman enhancement has spawned a DHS-on-steroids (heh) that can render its arrestees to internment camps without trial. The enforcement apparatus is nominally aimed at fighting neuroslavery, ghastly human trafficked sexbots, and apocalyptic cults whose followers are infected with god-viruses that make them worship the leaders as messiahs and render them pliant to their will. But the convention doesn't distinguish between hackers who conduct legitimate scientific inquiry and slavers and terrorists. Any advance in this sort of technology represents an existential threat to the human race, and it is not permitted, period.
Nexus tells the story of Kaden's kidnapping and blackmailing by the anti-trafficking enforcement side, who have the power of life and death over his friends and their wider circle of pals/experimental subjects. He is turned into an intelligence asset, charged with militarizing his research, and sent to entrap one of China's leading neuroscientists.
What follows is a beautifully plotted thriller, one that is full of delicious, thoughtful moral ambiguity. The power and cost of technology is thoroughly examined, turned over and peered at from every angle, and even the worst bad guys have at least a colorable claim on our sympathy at one moment or another. Naam is a hacker-turned-futurist who's run a nanotech startup, so the nerdly stuff all has the ring of truth. This is combined with excellent spycraft, kick-ass action scenes, and a chilling look at a future cold war over technology and ideology, making a hell of a read.