Open Radar

 
Summary:
Only a single user per computer is allowed to use iTunes in the Cloud at one time. This makes it easy to ruin another person's iTunes experience (this is especially the case on a family computer or a Mac with guest access enabled). Simply enabling iTunes in the Cloud for a short time is sufficient to revoke all access to iTunes in the Cloud or iTunes Match for all other users for 90 days. This action cannot be prevented or undone and considering that no administrator credentials are required, this action can be endlessly repeated every 90 days without permission or consent of other users and without leaving any trace.

Steps to Reproduce:
- Log in as guest on a Mac that has a user with iTunes Match enabled.
- Download a previous purchase through iTunes or enable iTunes in the Cloud with a different account.

Expected Results:
Either administrator credentials are asked to unassign the previous account, or both accounts get access to iTunes in the Cloud.

Actual Results:
The previous account gets unassigned. The other user cannot undo the action for 90 days and never receives any notification or warning that his account has been unassigned.