Social networks designed to aid businesses and their employees are potentially putting both at risk.

Sites such as Facebook and LinkedIn are becoming increasingly important to enterprises, but can compromise corporate and individual security if not closely monitored, say experts.

Web security firm WorkLight pointed to a recent outbreak of phishing attacks on Facebook as an indication that the social networking service has become a corporate security risk.

"Companies currently gain substantial B2B and B2C benefits by using social networking sites to uplift sales and promote products and services," said David Lavenda, vice president of marketing and strategy at WorkLight.

"Yet as phishers target Facebook users, secure access to these sites is a must-have on the security front."

Facebook has long been among the list of web-based services and peer-to-peer applications classified by security experts as 'greynets'.

These are programs which pose a security risk because they are difficult to monitor and control with conventional administrative and security software.

However, the risk from social networks may go beyond conventional cyber-crime. Security firm Aladdin noted that LinkedIn could unwittingly become a market for corporate espionage.

Aladdin explained that when users update their information, a list of each company's new hires and promotions is compiled. By analysing this information, a company could figure out a competitor's strategy and possible initiatives.

"Corporate 'spying' has never been easier. This new trend raises discomforting corporate data issues of disclosure and control," the security firm said.

"Companies and organisations have little or no control over the information their employees share on social networks, and individuals generally make no distinction between public or confidential corporate data that they disseminate. "