Internet speeds around the world have noticeably slowed down due to a massive "distributed denial of service" attack, reports the BBC.
These DDoS attacks bombard targeted web servers with so much dummy traffic that people trying to access a site for legitimate purposes are unable to do so. It's most analogous to a traffic jam on a highway with no one able to move.
The BBC says that security experts are describing it as "the biggest cyber-attack in history."
