You've probably heard a story that goes something like this: You've been thinking about where to go on vacation. You've discussed with friends and family and you think Cuba might be fun. Lo and behold, an ad pops up as you're mindlessly scrolling through your Instagram feed trying to sell you discount flights to Havana – and this is before you've done any online research into the trip. Has your phone been listening in to your conversations? Or is it a coincidence? After all, Cuba is a popular destination and lots of people book vacations this time of year.
The "my smartphone is recording everything I say and using it to sell me stuff" conspiracy theory has been doing the rounds for a while now. To settle the argument, computer scientists at Northeastern University, Massachusetts, conducted a year-long experiment into the matter.
So, is your phone listening to you? Probably not. The researchers found no evidence to suggest your smartphone's microphone is being used to tap into your conversations, though they have held back from saying the study is 100 percent conclusive. Instead, they uncovered another sinister technique, which app companies are using to siphon off your data.
The study monitored traffic from 17,260 Android apps using 10 phones and an automated system, keeping an eye out for any unusual activity and, in particular, any suspicious media files being delivered to third parties. Over 9,000 apps had permission to access the phone's microphone and camera, meaning they *technically* did have the right to listen in when the app was in use.
At no point did the researchers see an app activate the microphone to record a conversation or send an audio file without prompt. They did, however, notice that screenshots and video recordings of people’s activity in apps were being sent on to third parties without asking for consent. An example of one such app is GoPuff, which is a Deliveroo-type service that specializes in sweet and salty snacks.
While the experiment appears to debunk the "listening in" theory, the researchers stress it cannot be used ruled out the theory entirely. The study is yet to be peer-reviewed and the phones were operated by an automated system within a lab, not a person going about their usual business. Microphones may be triggered by movement or human contact.
As for the accuracy and sometimes eerily coincidental ads you receive, other factors may be at play.
“What people don’t seem to understand is that there’s a lot of other tracking in daily life that doesn’t involve your phone’s camera or microphone that give a third party just as comprehensive a view of you,” one of the authors, David Choffnes, told Gizmodo.
The research is due to be presented at the Privacy Enhancing Technology Symposium Conference in Barcelona next month.