Itunes blocks you from sharing music with YOURSELF, on your own computer

Rael has discovered another "feature" of Itunes: if you leave a copy of it running in one of my user accounts and switch to another, I'm blocked from launching it. That's right, Itunes is set up to keep you from sharing music with yourself.

It's silly enough that I can share my tunes across my home network yet
I can't share them with someone on the same machine. Despite keeping
all my music in /Macintosh HD/Users/Shared/Music,
I still have to wander from account to account adding each new CD or
Itunes Music Store purchase to each user's library just so that we can
share _our_ (defined in the strictest sense) music. Surely your Itunes
library on the local machine should show up in my Itunes window just
like any other network-shared Itunes library?

You cannot open the application "Itunes" because another user has it open.
Ask the other user to quit the application, then try again.
[OK]

No, not OK.

Should I mistakenly leave "my copy" of Itunes open and wander off
for a bit, there's no music for anyone until my return. No music for
you! Nobody but an administrator capable of killing off other logins
and processes has the ability to rectify this situation. Should every
user really need to be an administrator to truly share this multi-user
environment?

Link/Wayback Machine snapshot

Here's how to hack iTunes to play in multiple accounts