I see very strange behavior when using shared photo stream.
Just deleted photos from iPhone library (Camera Roll) and the pictures I had saved to a shared photo stream were deleted as well.
Do shared Photostreams just link to pictures you have stored locally? If this is the case, it makes the service of very little use to me.
Is there a way to delete photos on iPhone without affecting Shared Photostreams?
Note: I saw the same issue when reorganizing photos in Aperture. Suddenly the pictures I had moved within Aperture to another project disappeared from shared photo stream.