Companies should establish "very definite" policies regarding the issue of what staff are and are not allowed to do on the internet.

This is the opinion of Ben Camm-Jones, news editor of Web-User magazine, who said that such stringency would ensure there was a clear set of guidelines should a dispute occur.

Additionally, clear policies can allay IT managers’ concerns over employees wasting time or risking company security through malware, he continued.

Mr Camm-Jones said: "If there is ever any doubt then you can refer back to [the guide] and see for sure what it is and [it can help] a lot of IT managers [who] are very concerned about the sites that people visit."

According to figures produced by F-Secure in June 2008, 900,000 detections of malware occurred towards the end of the 30-day period, compared to 500,000 at the end of 2007.