A couple of years ago, Jack found some anomalies in which machines would stop working in some very specific circumstances while being scanned. A few experiments, tons of reading through documentation, and one mysteriously named tool called "sockstress" later, and the two are now touting a nearly universal denial-of-service (DOS) attack that can be performed on almost any normal broadband Internet connection -- in just a few seconds.
The TCP stack crashes on machines being attacked, meaning that in most circumstances the whole node needs rebooting to restore service.

Dark Reading - New DOS Attack Is a Killer - Snake Bytes