The use of social networking for business purposes has risen hugely during the last six months, resulting in a wide range of business and security risks which pose much more serious issues than potential productivity losses.

That is the view of next-generation firewalls provider Palo Alto Networks, which released the data in a study at the beginning of the week.

Graham Cluley, the senior technology consultant at Sophos, said that a major problem is when users share too much information on social networks, which could lead to professional hackers using the data to get details from small businesses in IT which the person is affiliated with.

He added that quite a disturbing thing to come out in his company's research was that 33 per cent of internet users use the same password for absolutely every website they use.

Mr Cluley continued: "That means, if hackers grab your password on one site, they can use it to unlock everything else about you. Chances are that you also use that password inside your company."

More than half of small businesses (53 per cent) believe that the most important benefit of outsourcing is guaranteed response times for IT support. London-based Connect conducted the research in 2007.