Is Time Capsule default public when being listened to?

[sendsent]

For example, I can see someone on Friend Activity who is listening to their Time Capsule and it has all their songs on it, but they said they never made it public. I guess that's also how the at the end of the year Spotify generates a most played songs playlist for each listener and I think those may be similar. I know that playlist is not public in the listener's profile where it shows public playlists, but i'm talking about Friend Activity and how it appears to be public through that component on Spotify Desktop.

Does anyone know why this is?