More than two in five (42 percent) of Brits post their date of birth on social networking sites, such as Facebook and Twitter, says Bullguard.

Research by the security firm also revealed 18 percent publish their telephone number online. Furthermore, more than a quarter (28 percent) allow their usernames and passwords to be remembered on PCs and other devices they use to access the sites, while 14 percent do the same for bank details.

More than a third (36 percent) post their pets names on Facebook and Twitter, while nearly a quarter (24 percent) share their children's names and seven post reveal their address. Worse still is the fact 11 percent admit to posting photos of high-value cars and other goods and more than a third admit top updating their profile from holiday alerting other social networkers to their fact their house remains empty.

"Though this sort of information may seem harmless to share with others, much of it is commonly used as security questions when accessing an online bank or confirming identity over the phone," says Claus Villumsen, internet security expert at BullGuard.

"It's also a bad idea to publicise the fact that you will be away for any period of time, especially if the house will then be empty, as this just gives more information to would-be thieves as to your whereabouts".

Bullguard advised web users not to post these types of details as well as never accepting friend requests from people you don't know and spend some time learning how to restrict which information you make public.