Asked by: Chris Menzies, Cardiff
Figures from information security firm Symantec say that 68.8 per cent of all emails are spam. But that alone is not enough to slow the internet. Cloud security firm Incapsula reckons that botnets drive 61.5 per cent of web traffic. These networks of hijacked computers are used to blitz servers through so called DDoS attacks. Individual networks can be incapacitated for a while, but the internet is a network of networks. Slowing it is virtually impossible.
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.