Crashing websites and overwhelming data centers, a new generation of cyberattacks is costing millions and straining the structure of the Internet.
While some attackers are diehard activists, criminal gangs or nations looking for a covert way to hit enemies, others are just teen hackers looking for kicks.
Distributed denial of service (DDoS) attacks have always been among the most common on the Internet, using hijacked and virus-infected computers to target websites until they can no longer cope with the scale of data requested, but recent weeks have seen a string of particularly serious cases.