Tokyo police have arrested a man for allegedly sending 2.2 billion spam messages, according to news reports.
The 25-year-old named Yuki Shiina allegedly bought 600,000 e-mail addresses off the internet for £450 and earned over £9,000 from the spam campaign that promoted online gambling and dating sites.
Police acted after an internet service provider complained about the volume of spam. It appears that Shiina faked the sender information on the e-mails in an attempt to avoid detection. This broke Japanese laws and allowed police to act.
Graham Cluley, senior technology consultant for security software vendor Sophos, said, "No-one who hears about a single person believed to have sent 2.2 billion spam e-mails can be in any doubt as to the scale of the problem."
Mark Murtagh, technical director of Websense, an internet filtering firm, said 74% of mail aimed at corporate addresses was spam.