The European Network and Information Security Agency (Enisa) has released a new report into the dangers of using social networking sites, particularly from mobile phones.

Enisa outlined a number of risks and threats associated with using the sites, and advised individuals and organisations to follow 17 golden rules.

Many people use their mobile phones to access such sites, and Enisa warned users to keep them secure and try to avoid any business information falling into the wrong hands.

The Online as soon as it happens report said that the growth in the use of social networking sites has been so great that malware writers are enjoying rich pickings. The report therefore advises users to change their online routine.

Studies in Europe have found that users have a very basic level of security awareness about social networking sites, and the report identifies the risks, and suggests ways to avoid falling victim.

The biggest risk for companies is information leakage. Enisa cited one case of a university professor who had suffered when someone created an offensive profile for him on Facebook, and another in which Virgin Atlantic had disciplined 13 employees for posting comments criticising passengers.

"This report provides practical, hands-on advice on how to stay safe online, anywhere and anytime, when enjoying mobile social networks," said Dr Udo Helmbrecht, executive director of Enisa.

The guide includes simple steps, such as always logging out once a session is over, and not using auto-complete tools to fill in passwords and other forms. Workers should also not mix work and personal contacts, Enisa warned.