Scott Fortnum had put in almost a full day of work at his Markham, Ont., office when he decided to "check in" on Foursquare, a location-based social network where users log the names and co-ordinates of the places they visit with a time stamp.
The 44-year-old's check-in was marked with a small coral balloon on an embedded Google Map and instantly viewable by the 12 friends he lists on Foursquare - and millions of others.
His check-in found its way onto pleaserobme.com, a recently launched website with a mischievous mandate: "listing all those empty homes out there."
With March break approaching, many impending vacationers are installing automatic timers on their lights and putting their newspaper subscriptions on hold to deter burglars. Many are also posting on Twitter about when they're leaving and touting their week-long getaway to Jamaica on Facebook - unwittingly letting the online world know exactly when they're away.
Mr. Fortnum's check-in appeared this way on Please Rob Me: @sfortnum left home and checked in 30 minutes ago: I'm at ALS Canada (3000 Steeles Ave. E. #200, DVP & Steeles, Toronto.) http://4sq.com/4MmX51
Many Foursquare users such as Mr. Fortnum cross-post their check-ins to Twitter, where they are easy to find through the search function. With some simple coding, Please Rob Me's creators are able to collect those millions of public tweets on their site in real time, highlighting one of the many security concerns that springs from broadcasting one's whereabouts online.
Frank Groeneveld, one of the three students from the Netherlands who designed Please Rob Me, says he co-created the site to give members of social networks a wake-up call.
"They think the Internet is anonymous, and it was a few years ago, but it's not right now. You can find almost anything about everyone," he says.
Just a day after the site went live, Mr. Groenveld received dozens of e-mails from people who had spied their own tweets on the site or been alerted to them by others. It prompted some to delete their accounts or to "protect" their tweets - hide them from people they weren't following.
U.K.-based Legal & General Insurance released a report last summer highlighting the security risks of publishing travel details on social networks. The firm polled 2,000 Facebook and Twitter users and found that 38 per cent posted holiday plans online.
"There are privacy settings on these sites, but people were really willing to put [out]information about holidays [and]recent purchases … that raised potential for their information to become available to potential burglars," Garry Skelton, a spokesman for Legal & General, says. He says such details could be used conjunction with Google Street View to execute "smarter" thefts.
Of course, even in the pre-Internet age, that information could be tracked down through phone directories and by physically driving down residential streets, but Mr. Skelton says social networks make things easier for burglars.
"The people who choose to pursue these lifestyles are quite enterprising," he says.
Limor Elkayam, a 30-year-old New Yorker who runs an online news site, parted ways with Foursquare after using it for just a few weeks when she got a glimpse into how her seemingly innocuous check-ins could be picked up by unwanted people.
Last month, while sipping lemongrass tea at a local chocolate shop, she checked in on Foursquare, thinking nothing of it.
When she got home, she was greeted with two messages. One was from a man she knew on Twitter but had never met. He wrote that he was near the chocolate shop himself, but that she shouldn't worry because he wouldn't actually "come stalk her." The other message was from a former co-worker, who said if someone wanted to assassinate her, it would be very easy.
She says she understood the messages were sent in jest, but they still gave her the chills. "I thought, 'Oh, that's not funny.'... [Foursquare]has some great features, but it also has some creepy features."
Dave Drager, who is completing his master's thesis on location-based social networks at West Chester University in Pennsylvania, suggests the normalization of online over-sharing means most don't give a second thought to what they post since "everyone else is doing it."
"Some [friends]started checking in at banks and it just clicked in my head - you shouldn't be broadcasting that stuff. There's definitely some security implications to divulging where you're going and the sources that you use," he says.
As for Mr. Fortnum, he wasn't fazed when he found out his check-in had made it onto Please Rob Me. He regularly checks in at home in Innisfill, Ont., though he only lists a rough location rather than the exact address. He says he has no plans to change his online sharing habits.
"I know for sure my dog is home and I have neighbours on both sides [of my house]" he says. "If I were a young, single urbanite it would be more of a concern to me, but as an older family person in the 'burbs, it doesn't concern me," he says.