The number of bots or compromised computers sending out spam each month across Europe has quadrupled according to antivirus company Trend Micro.

In a direct attack on ISPs for failing to do enough to curb the problem Dave Rand, CTO of Anti-Spam at Trend Micro, says "ISP's can see this type of criminal activity happening and still refuse to accept responsibility".

This research comes day after Ispa, the UK's internet service providers' association, provided evidence to the House of Lords Science and Technology Committee on the issue of personal internet security and spam.

According to the company top ISPs are not doing a great deal to overcome the growing problem of botnets and the amount of spam they send out.

Trend Micro says it has found that the number of compromised computers sending spam has more than quadrupled across EMEA this past year. In January 2006 there were 1.6 million and now there are 6.89 million compromised PCs sending out spam.

In the US, the FBI believes that internet crime is now a bigger business than the drugs industry and according to the company we are likely to see this pattern follow in the UK.

"These online criminals are highly sophisticated and ISP's need recognise the severity of this problem and act on this urgently", said David Rand who, unsurprisingly, suggested that to protect themselves, users should always have an updated antivirus program running, preferably its, no doubt.