Strange playlists appearing when on a network

Q: I am starting to get blue playlists in my iTunes window containing music that I have not placed in my computer and is not in my library. As I’m writing this, another one was just added to the Shared Music list. What is this? How is it happening? How can we stop it? One Shared Music Playlist is over 7 gigs of info, we cannot keep filling up our computer like this.

– Pam

A: Not to worry, Pam… this is “working as designed,” and you’re not using any of your hard drive’s capacity. You’ve inadvertently discovered iTunes’ Music Sharing feature. The “Blue Playlists” you mention are not playlists at all, but rather are the remotely stored music libraries of those on your network.

If you open one, and attempt to play a track, the audio is “streamed,” or transferred temporarily in real-time, to your computer. Similarly, others on your network can likely see and listen to (but not take!) your music. Simply, it’s near harmless if left alone.