A lawsuit filed this week in Chicago alleges that Bose headphones “spy” on listeners. Michael Tsai has a good list of links about what this means:
I downloaded the app on android and listened to a few songs on Spotify to find out what information was being sent.
While the app is running, the app sends a HTTPS request every time the track information changes or the volume changes. When the track information changes it sends the artist, album and song name. When you change the volume it sends the new volume level.