Ars Technica reports that it was able to reproduce the issue with ease, noting that the Spotify app for both Mac and PC was writing 5 to 10 GB of data in less than an hour. It continued to do so when the software was idle as well. I was also able to observe similar activity on my Mac when streaming songs like I normally would. Some users report in the aforementioned forums that the app wrote as much as 50GB of data even when it was left idle overnight.

The good news is Spotify has addressed the problem with an update to version 1.0.42 on the desktop. It's rolling out now, so you'll want to download it as soon as possible if you access the streaming service on your computer. If you aren't alerted to the version, check for it in the Preferences menu by clicking "About Spotify" down at the bottom.