Recently, I've noticed my Instagram app displaying a remarkable amount of intuition in how it feeds ads to me. The day after discussing a particular flavor of a particular brand of a meal replacement drink at my friend's home (a brand I never googled or emailed about before) an ad for the exact same drink appeared in my queue. Today while driving along 14th Street in Manhattan, I remarked that I was surprised to see signs indicating a Target would be opening there soon. A short while later ads for Target popped up. Could it be that Instagram is using the microphone on my iPhone to listen to my conversations?
There certainly is a good deal of speculation online that Instagram, Facebook, and other apps listen to conversations spoken within range of the smartphone on which they are installed. See for example this Redditt board. Could it be that this is really taking place?
Antonio Garcia Martinez, a Facebook employee responsible for ad targeting, published an article in Wired this past November attempting to debunk this idea. In Facebook's Not Listening Through Your Phone. It Doesn't Have To, Garcia Martinez claims that voice over internet data for even half a day would amount to 130 MB per user (3KB per second). This much data for all 150 million daily users of Facebook in a single day would come to 20 petabytes. According to Garcia Martinez Facebook only stores 300 petabytes of data, taking in 600 terabytes each day. Facebook uses about 1 million target keywords, and searching for that many terms would cause a substantial decrease in a phone's performance. A test at Facebook, 'Project Chorizo', utilizing all available user data indicated that only a single digit percentage of posts provided useful data to the ad targeting algorithm.
On the other hand, Zoe Kleinman, a technology reporter for the BBC, in her March 2, 2016 article, Is your smartphone listening to you? indicated that it is indeed technically possible for an app to scan conversations. She engaged a cyber security experts from Pen Test Partners who in just two days were able to create an Android app that could listen in on conversations and then convert the spoken words to text that was transferred to their computer. Kleinman reports that:
It wasn't perfect but it was practically in real time and certainly able to identify most keywords.
The battery drain during our experiments was minimal and, using wi-fi, there was no data plan spike.
"We re-used a lot of code that's already out there," said David Lodge.
"Certainly the user wouldn't realise what was happening. As for Apple and Google - they could see it,
they could find it and they could stop it. But it is pretty easy to create."
A Google spokesperson questioned for the article noted that apps are restricted from collecting data without the knowledge of users.