What does the internet know about your friends and private life?

The internet is increasingly a place where we keep in touch with friends, family and colleagues, using email, blogs and social-networking services such as Facebook and Twitter. But everything you do or say online leaves a digital trace, no matter how private you might think your actions are.

In this article we’ll explore just how much information people inadvertently broadcast on the web and how easily this information can be obtained and used even by those without specialist knowledge. In short, we’re turning cyber-stalker.

But simply scaring the wits out of people won’t help anyone. So once we’ve shown how easy it is to unearth personal and private information about our victims, we’ll also explain what to do to prevent becoming a victim yourself.

Our starting point
We secured the agreement of several Computeractive family members to act as willing prey and all private information revealed in this article is real. All we had as a starting point was our victims’ names (which we’ve changed here) and a rough idea of where in the country they lived – the kind of information a would-be stalker could easily pick up at a business meeting or party, say.

Let’s go stalking
Jen uses Facebook regularly and wants old school friends to be able to find her, so she doesn’t mind her name appearing in Facebook’s search feature. Her Facebook username incorporates both of these, making her easy to find.

We logged in to Facebook as an ordinary user, with no shared friends, found her and browsed 93 photos in an album she had forgotten to make private. Among them was a picture of a ticket to a fitness class that was uploaded several days before the event – gold dust to stalkers like us.

A comment on a photo of Jen’s children, mentioning 'my gorgeous niece and nephew', introduced us to Jen’s sister, Elizabeth. The children are Amy and Ryan, aged four and seven in 2011, with birthdays in July and August respectively – according to the decorations and posting dates on two photos of birthday cakes.

We followed the link to Elizabeth’s profile, which is hidden from Facebook searches, but shows up in comments on other people’s public posts or photos. Her photos, comments and personal info were hidden, but her secondary school, ethnicity, birthplace and birthday (but not her age) were on public view, as were some of her personal tastes in music, movies and fashion. Helpfully, she also uses her full name.

Via a Google search we found that Elizabeth was once a company director for a now-dissolved company. A free company director search gave us her month and year of birth and a home address. A Google search also revealed that Elizabeth and Jane’s father had uploaded a family tree to Genealogy's website and forgotten to make it private. This gave us names and relationships dating back to the late 19th century.

The address led us (via BT directory enquiries) to a landline telephone number registered in her father’s name, so it seems likely that Elizabeth lives at home. A free search of electoral roll, thanks to the 192 website, confirmed this and Google Street View gave us a nice look at the bungalow, with a green Skoda Octavia Mk1 (facelift model, 2000-2004) estate car parked in the drive.