Social networking sites such as Facebook and MySpace are potential security risks to companies

Social networking sites such as Facebook and MySpace are potential security risks to companies, IT experts have warned.

IT security and control firm Sophos warned that a large number of Facebook profile pages contain users’ current employment details, which could be used by cybercriminals to commit corporate fraud, or to enter company networks.

A survey conducted by Sophos found that 41% of Facebook users were prepared to divulge personal information to a complete stranger.

And firms are beginning to cotton on to the dangers, as a separate poll of 600 workers found that 43% were denied access to Facebook by their company, while 7% said that usage was restricted to specific business requirements only.

However, 50% of respondents said that their company did not block access to Facebook, with 8% in fearing an employee backlash.

Graham Cluley, senior technology consultant at Sophos, said some firms believe Facebook to be a procrastinator’s paradise, leading to careless use of the site.

He said: “If workers are allowed to be given access to these sites, then it’s imperative they are taught best practice to ensure they are not putting their personal and corporate data at risk. Five minutes spent learning the ins and outs of Facebook’s privacy settings, for instance, could save a lot of heartache later.

“More businesses are restricting access to these kinds of sites. Companies are increasingly looking to secure and control their workers’ web activity because of the impact it can have on the company in terms of productivity, bandwidth and security,” Cluley added.

Employees’ access to Facebook has already been banned by a number of firms, including Transport for London, LloydsTSB, the Metropolitan Police and Credit Suisse.