Trust Me by Jeff Abbott

The new thriller from the bestselling author of Collision Luke Dantry works anonymously from his computer, a mild academic hired by a Washington think tank to bring out Internet extremists who vent online. It's an incendiary network of rage0filled, mentally suspect, and mostly impotent loners he calls the Night Road. But if Luke thought his identity was safe, he was wrong. The Night Road is more organized and dangerous than he imagined. And they aren't the only ones who've been watching him.