Almost three quarters of the users of social networking sites surveyed gave out personal identifying information over the sites, according to corporate computing firm CA.
Personally identifying information was given out despite the fact that 57% of those surveyed are worried about becoming a victim of cyber-crime. Personal details are very useful to identity thieves who can use them to access bank accounts or to gather further personal information.
"Giving out a social security number, paired with a birthday and name, could provide enough ammunition for criminals to hack into financial records and compromise users' personal information," said Ron Teixeira, executive director of the National Cyber Security Alliance in the US.
Over 2,000 adults were surveyed by CA about their use of social networking sites, which have enjoyed a wave of unprecedented recent success, with market leader MySpace claiming that it has 107 million users.
The growth and management of social networking and other new internet tools will be the subject of upcoming OUT-LAW seminar 'Legal risks of Web 2.0 for your business'.
The survey found that 46% of the users who had access to a work computer carried out social networking at their office. That, says CA, opens employers up to some of the liabilities inherent in online social activity.
"As social networking use continues to increase in popularity, it is imperative that people take steps to safeguard their information at home and at work," said David Luft, senior vice president of product development at CA.
"Not only is it important to install and frequently update firewalls, anti-spyware and anti-virus software, users must be aware of the specific unsafe behaviours which make them vulnerable to online predators, hackers and thieves," said Luft.
Security firm Context Information Security, though, said that the technical threat is not as great as CA implies. "The risk is a little over-egged as corporate security is typically vastly superior to that of Joe consumer, this shouldn't be a threat to businesses," said Steve Matthews, security advisor at Context.
Most corporate usage policies forbid the accessing of sites such as MySpace and the carrying on of social activities online at work. Matthews said that this and the productivity losses stemming from social use of technology, were the issues that companies have to address.
"This is more of a productivity issue than a security problem," he said. "Businesses should already have solutions in place to address malware such as the viruses, Trojans and worms. So the real risk here is where such solutions haven't been implemented, or have been configured incorrectly – only then could this be a major problem and security threat."
Despite the common view that social networking is a teenagers' phenomenon, the survey found that older adults make up a significant proportion of surfers. Just under half of the adults surveyed participated in social networking, and over half of them were over the age of 35, the survey found.
The legal risks of social networking and other aspects of Web 2.0 are addressed in OUT-LAW's Breakfast Seminars, taking place across the UK from 17th October.