A increased wave of spam has been predicted this year as cyber criminals are increasingly targeting social networks such as Facebook. The networking computer company Cisco estimated that worldwide spam volumes this year could rise by 30 to 40 per cent compared with 2009. Spammers already send out up to 100 million junk e-mails a day and, although the vast majority are never opened, enough people click on the links to make spam a multimillion-dollar industry.