It's become commonplace for security reporters and providers of security technologies to find themselves targets of hackers' wrath, especially when they put criminal activity under the spotlight. Earlier this year, Brian Krebs had done some work to expose a "booter" service. Like other public security figures, he found himself the target of repeated DDoS attacks. In Brian's case, this culminated in a "SWATting" attack -- a surprise visit by dozens of heavily armed police at his front door. Research on "booter" services reveals a relatively unsophisticated, but high-profit criminal community of DDoS-for-hire web sites that are capable of considerable impact. They operate under legal auspices, leveraging legitimate DDoS protection services. Anyone with an axe to grind and a small amount of money can hire one of these services to have virtually any person or web site knocked off the Internet. As an indicator of how mainstream these services have become, most of them accept payment via Paypal. This talk will delve into the recent proliferation of these malicious commercial DDoS services, and reveal what's been learned about their surreptitious functioning, exposing the proprietors behind these illicit services, and what is known about their targets and their thousands of paying customers. Emphasis will be placed on detailing the vulnerabilities present in most booter sites, and the lessons we can draw about how targets of these attacks can defend themselves.