Attacks on company and Government internet sites spike during school holidays when the main culprits - schoolboys - spend time in front of their computers rather than in the classroom.
There were almost 400,000 attacks on websites around the world last year, a surge of 36 per cent from 2003,said a report by internet watchdog agency Zone-H.
The main targets are US military websites, which are attacked by anti-Iraq war protesters, and large companies and Governments, which attract anti-globalisation protesters.
