There's also the issue of jurisdiction. If the crime is originating across some border (which more than likely it is), there's probably not much they're willing to do about it.
Exit node ip, that's the last ip-address right? There was something in PHP I did recently that did that, gave you the last ip. Maybe I'm mistaken.
E.g. these are the Spanish ones:
https://www.gdt.guardiacivil.es/webgdt/home_alerta.php
http://www.policia.es/org_central/judicial/udef/bit_alertas....
Meanwhile, if I were to deliver this info to my local police department, I have very little faith they'd even know what I'm talking about.
Skype is also well-known among current chinese college students.
Basically, I think it's unlikely that anyone in their early twenties has never heard of skype.