Blighty Facebook users are going to have to stump up more cash for their home and contents insurance because the greedy insurance companies are convinced that they are bigger risk.

Legal & General claimed that its survey of 2092 social notworking users found that they were terminally stupid when it came to revealing details about their lives. Nearly four in 10, or 38 per cent, of people using social networking sites such as Facebook or Twitter post details about holiday plans and 33 per cent post details of a weekend away.

One insurer said that his company was planning to use Legal & General's report to jack up insurance premiums for households that use social networking sites. Coupled with the finding that an alarmingly high proportion of users are prepared to be 'friends' online with people they don't really know, this presents a serious risk to the security of people's home and contents, the insurer said.

The report called The Digital Criminal, Legal & General said people used social media sites to connect with people who were essentially strangers, which could provide potential thieves with vital, personal information.

More than 13 per cent of Facebook 'friends' were complete strangers and might just be thieves waiting to find out when the house was empty. Nearly two-thirds, or 64 per cent, of 16-24 year olds shared their holiday plans. Younger users were the most likely to give away information about their whereabouts.