Internet users are at an increased risk of web-based crime, despite 88 per cent having some form of internet security software, according to a poll by Get Safe Online.
The results of the survey into public attitudes to internet security were released at the start of the Get Safe Online 2007 road show.
The number of people using security software demonstrates an increased vigilance when it comes to protecting personal computers, but users' actions online put them at increased risk of internet-based crime.
Cabinet Office minister Gillian Merron told the annual Internet Safety Summit in London: "The internet is a fantastic tool, whether you use it at home, at school, at your local library or at work.
"The risks we are highlighting today can be easily fixed and do not mean that people should stop using social networking sites and wireless networks.
"People simply need to take a few basic steps and simple precautions to help keep themselves, their families and their businesses safe online."
Get Safe Online found that over 10.8 million people across the UK are registered with a social networking site, and that one in four have posted information such as phone number, address or email, increasing their vulnerability to identity fraud.
The research also found that 13 per cent of social networkers have posted information or photos of other people online without their consent.
This trend is strongest among younger users, according to the poll. Around 27 per cent of 18 to 24 year-olds have posted information or photos of other people without their consent.
"The popularity of social networking and other sites means that we are much more open about ourselves and our lives online," said Tony Neate, managing director of Get Safe Online.
"Although some of these details may seem harmless, they actually provide rich pickings for criminals. Your date of birth and where you live is enough for someone to set up a credit card in your name, for example.
"So while most people would not give this information to a stranger in real life, they will happily post it online where people they don't know can see it. "
