The teenage defendant in the case, who cannot be named for legal reasons, was charged under Section Three of the Computer Misuse Act which criminalises unauthorised access to or modification of computer systems.
But in his written ruling, District Judge Kenneth Grant of Wimbledon Magistrates Court said that although a lot of e-mails were sent, they could not be said to have caused unauthorised changes as defined by the act.
Interestingly enough, it turns out that (believe it or not!) denial of service attacks are not illegal under the current Act. However, it looks like the All Party Internet Group of MPs are looking to have the Act updated.