Cyber-attacks that bring down websites and online services have been getting bigger every year. But how will businesses cope in 2016?
Distributed denial of service (DDoS) attacks work by overloading websites or other online services with traffic.
They have the power to knock whole sites offline and are usually carried out by automated bots or programmes.
Victims of such attacks in the past month include the Irish National Lottery and the BBC while in 2014 the popular videogame Wurm was also hit.