A hacker who caused chaos with one of the world's most prolific computer viruses has been jailed for two years. Simon Vallor, 22, spent hours at his bedroom keyboard constructing "enticing" bugs in a bid to ensnare as many victims as possible. The so-called "mass-mailers" posed as innocent messages of love or timely warnings about security. In this way one of the viruses spread around the globe, infecting hundreds of thousands of terminals in 46 countries. It clogged up networks, caused computers to crash, affected institutions, businesses and individuals, and at its height at the beginning of last year was...