Owen Mundy knows where your cat lives and by proxy, where you live.

If you’ve ever shared a picture of your cat on Instagram or Flickr, you’re likely to find said picture on Mundy’s site: I know Where Your Cat Lives. Over a million cats from all over the world currently appear on the site’s map. Each photo was obtained through publicly available data – the geographic details provided by a smartphone when a person uploads a photo.

When you first visit the site, you’re presented with a picture of a cat with the image’s caption telling you where the image was posted. I played around with the map and narrowed down a search for the Greater Toronto Area. This was the result:

Map showing cats in the Greater Toronto Area

Kind of creepy, huh? Well, that’s the point.

I looked in my neighbourhood and didn’t find any pictures of my cat. I’m not surprised though since I’ve long since turned off any geo-tagging settings on my phone.

How did Mundy put this site together? It seems pretty straight forward but it actually required a ton of work. First, he wrote software to get access to the APIs from the photo sharing websites – all of which are open to the public for anyone to access. Next, he downloaded the photos and removed any identifying information – particularly the usernames of those posting the pictures.

Then he used a supercomputer at Florida State University – where Mundy is an associate professor – to create the cluster visualizations. Finally, he designed and coded the front end to put all of the cats on the map.

As to what prompted him to start this project, Mundy shares:

I have a daughter and had been posting pictures of her on Instagram for about a year, and then I realized that Instagram had created a map of every picture I had been sharing with the world. That scared me. So I thought, what’s the least creepy, most fun way to do this? It’s less likely someone is going to try to kidnap your cat, but, to a lot of people, their pets are like a child.

There are there are 15 million images tagged with the word “cat” with thousands more being uploaded every day. Think about how many must be tagged with “toddler”, “home”, “work” and countless other experiences we share every day. I’ve always been an opponent of sharing child photos on social media and I think people in general are too lax about their privacy when it comes to their social media posting habits.

If you do post a lot of photos online, be sure to take the extra steps of turning geo-tagging off in your phone’s settings. It also doesn’t hurt to check the geo-related settings on the social networks you’re posting to.

As for Mundy, the website has some great charts that really help clarify all of the data being utilized. There’s also a Kickstarter campaign available for anyone wishing to help with the site’s hosting costs.If you’d like to know more about Mundy, you can do so via his personal website.

Cat image credit: Tom Gill.