A creepy new app that lets your Instagram followers track your location has launched on iOS and Android.
The map updates in real time, and users can filter location updates from the last 24 hours, the last week, or the last month.
This gives your followers a quick and easy way to see the last location you shared, as well as any cafés or shops you frequently visit.
Depending on how much information you share, it could also be used to work out where you live and work, and when you are likely to be at each location.
Research conducted by Who’s in Town ahead of the launch reportedly revealed that 30% of people who post Instagram stories over the weekend geotag at least one location.
“The amount of data is insane,” Erick Barto, the app’s creator, told Wired .
“It’s the equivalent of you going through every single story and writing down every single location, just consistently all the time.”
The app, which costs either $6.99 per month or $69.99 USD per year for a subscription, has two viewing modes – general and single user.
General mode shows you a map of every place that all of the people you follow have said they visited, when they said they were there, and links to the post or story where they indicated that.
Single-user mode allows you to track a specific person. The other pins fade away, leaving only one user’s shared location history.
This could be used by stalkers to track targets, or by jealous partners to uncover secret relationships, based on similarities in the time and location of posts.
The information could also be used by companies to infer a person’s hidden habits or traits.
Who’s in Town can pull data from both public and private Instagram accounts – as long as the person signing into the app is an accepted follower of the private profile.
There is no way for Instagram users to determine whether one of their followers is using the app to scrape and aggregate their data, as it doesn’t require their consent.
Luckily, the app isn’t really meant to be used. It was developed to illustrate the wealth of sensitive data users willingly share on public platforms without considering the implications.
“People don’t realise what they’re sharing,” Barto said.
“They’re [operating under] the false assumption that this information is only going to a few people … but it’s public.”
Ultimately, Barto hopes that Who’s in Town’s unsettling demonstration of the potential for misuse causes Instagram to change the way it stores and permits third-party access to this type of data.
Last year, he developed a similar privacy-invading app called Chatwatch, which allowed users to spy on their friends by exploiting WhatsApp’s status feature, which shows when users are on or offline.
After an outpouring of concern from users, Apple and Google removed Chatwatch from their app stores, along with every other similar third-party app that scraped WhatsApp for the same type of user data.