Some good points the defence lawyer makes here.

Cobden pointed to the fact that, despite the deals struck between studios and BitTorrent business owners, the involved websites did nothing to discourage users from abusing BitTorrent to download copyright materials. He argues, on that basis, the studios are happy with this arrangement.

This argument has be used to fight AFACT's accusation that iiNet's inaction in deterring subscribers from copyright infringements equates to condoning the illegal activity, since the studios and partners themselves also took no action.

Cobden said that it was unfair to force iiNet to do the studios' policing work as they were effectively evading their own responsibility.

"[iiNet] doesn't want to be judge, jury and executioner," he said.

Cobden fended off claims by AFACT that the ISP was "rewarding" and "encouraging" copyright law breakers by offering to upgrade heavy users' download quota.

He said iiNet promoted users to move to a higher download cap simply so that they would not incur astronomical bills from excess data charges or to avoid the inconvenience of a slowed connection speed.

As for iiNet ignoring AFACT infringement notices, which were continuously sent to ISP, Cobden asked the court to acknowledge that iiNet's fellow ISP peers were also on the same boat.

Further evidence presented to the court suggests other ISPs that have been contacted by AFACT with the same infringement notices, including Optus and Telstra, have also not acted on them.

And this.
The Internet Industry Association wrote to copyright owners more than two years ago seeking to address piracy concerns, only to be told the Australian Federation Against Copyright Theft would instead start taking service providers to court.
The IIA wrote in April 2007 to Australian Recording Industry Association (ARIA) chief Stephen Peach, Music Industry Piracy Investigations (MIPI) general manager Sabienne Heindl and AFACT boss Adrienne Pecotic seeking a better understanding of its notice and disconnect proposals but says it was rebuffed.

Yeah, why negotiate when you can just sue!