The music industry opened up a new front in the war on online music piracy yesterday, threatening to sue internet service providers that allow customers to illegally share copyrighted tracks over their networks.

The International Federation of the Phonographic Industry, or IFPI, said it would take action against internet companies that carry vast amounts of illegally shared files over their networks. It stressed that it would prefer not to pursue such a strategy and is keen to work in partnership with internet providers.

John Kennedy, the chairman of the IFPI, said he had been frustrated by internet companies that have not acted against customers involved in illegal activity. He warned that litigation against ISPs would be instigated "in weeks rather than months". Barney Wragg, the head of EMI's digital music division, said the industry had been left "with no other option" but to pursue ISPs in the courts.

What do they expect? ISPs to inspect every piece of traffic that goes over their networks? Have they even thought through the repercussions of that?