But according to cyber safety experts, such posts are a gift to burglars and stalkers.

``Not only are you telling me where you are, you're telling me where you're not,'' cyber safety consultant and former police officer Susan McLean said.

``And I could get that photo, run it through a program and find out exactly where it was taken.''

One New South Wales family learnt just how dangerous this can be when they were robbed at knifepoint recently, hours after their daughter posted a photo of her grandmother's savings - in cash - on Facebook.

Just before midnight, two men broke in and demanded to speak to the girl, who was not home. They then stole money and property from her terrified mother.

Most people who are burgled put it down to bad luck, Ms McLean said.

``No one ever thinks their Facebook posts had something to with it. And because police don't ask about social media when they attend burglaries, we have no idea of the extent of the problem,'' she said.

Victoria Police said it was considering whether to include social media usage in its crime reports.

Concerned by the possible link between ``location sharing'' and home invasions, insurance company AAMI researched its customers' social media habits.

It found that one in five specifies when they will be away - or where they are at certain times - and almost a third upload pictures while on holiday.

More than one in 10 use the location-sharing features.

``It's difficult to attribute a particular break-in to a social media posting, mainly because burglars don't tend to tell their victims why they picked their home,'' AAMI spokesman Reuben Aitchison said.

``But telling the world when you're not at home is a serious threat to your house and your belongings.''

Yet even those who don't declare their location could inadvertently reveal it through their photos.

Most smartphones automatically ``geo-tag'' the precise latitude and longitude of where each picture was taken.

Burglars or stalkers can then extract this data, punch it into Google Earth and get a street view or address within minutes.

While Facebook and Twitter strip these geo-tags from photos, they remain embedded in images uploaded through third party applications such as Twitpic.

Photos sent via SMS or email, or posted on blogs or other social media sites, are also vulnerable.

To test how easily location data can be extracted from photographs, The Sunday Age asked a Melbourne IT specialist to track the location of a picture posted via Twitpic.

It took him just seven seconds to find the address.

Such technology makes ``sexting'' - the sending of explicit images via SMS - even riskier.

Should the photo contain a geo-tag, the subject could easily be tracked, especially if the picture ``goes viral''.

``It's chilling to see how easily this can happen,'' said Rosalie O'Neale, senior adviser for the federal government's Cybersmart program.

``It's very important that people check their phone setting and allow only the location services they want.''

In 2010, Guardian journalist Leo Hickman demonstrated the dangers of smartphone apps such as Foursquare, in which users share their location with friends - and nearby strangers, if they choose.

Hickman quickly found ``Louise'' in a pub, whose profile included her surname and a photo.

He then trawled through her Twitter account and looked her up on Google, discovering where she worked, which train she caught and where she shopped the night before.

After approaching her and revealing his cyber-hunt, Louise described it as ``a little unnerving, to say the least''.

``We're not out to scare people,'' Ms O'Neale said, ``but we need to be clear: you must check your privacy settings and be very careful about the information you send out.''