Ah I see, thx Volv....
Anyways, I already explained
here that such a thing is not a solution as it most likely will never happen because Patchou isn't going to abuse the protocol for something like this. Moreover, you are going to flood the MSN server without a doubt with something like this. Result: MS will take drastic steps and is for sure not going to tolerate it. And other tools and addons which currently use the protocol (but don't flood it) are going to be punished too...
The same thing for when you implement something for only between aMSN clients. Be be sure that if you are going to implement something like this between aMSN clients only (so that aMSN users can send sounds between them) using the MSN network that MS isn't going to tolerate it either. And that it is again quite possible that MS is going to take steps also and filtering out any protocol message which doesn't come from Messenger itself and/or even cancelling user's connections, etc...
Now, I can't speak in Patchou's name, but I'm 99,999...% certain he would say something very similar.
/ 
