This is an interesting and accessible article on the DDoS extortion business and companies that offer protection services.
The Zombie Hunters — On the trail of cyberextortionists, Evan Ratliff, The New Yorker, 10 October 2005
“One afternoon this spring, a half-dozen young computer engineers sat in the headquarters of Prolexic, an Internet-security company in Hollywood, Florida, puzzling over an attack on one of the companyâ€™s clients, a penile enhancement business called MensNiche.com. The engineers, gathered in the company’s network operations center, or noc, on the fourth floor of a new office building, were monitoring Internet traffic on fifty-inch wall-mounted screens. Anna Claiborne, one of the company’s senior network engineers, wandered into the noc in jeans and a T-shirt. The MensNiche attacker had launched an assault on the company’s Web site at 4 a.m., and Claiborne had spent the night in the office fending it off. “Hence,” she said, “I look like hell today.””