In Australia it was determined that an ISP bears no responsibly to respond to allegations of copyright infringement by ISP users.

https://en.wikipedia.org/wiki/Roadshow_Films_Pty_Ltd_v_iiNet...

Of course Telco's can choose to be involved, perhaps accept payment to lookup and snitch, etc. but for the most part a number of ISPs in Au just wash their hands of devoting resources to play connect the dots for others.