BMG Rights Management and Round Hill Music have filed a lawsuit against US ISP Cox Communications, claiming that the firm has deliberately failed to stop its customers pirating content.

The publishers say that Cox Communications has been notified of copyright-infringing activity by its customers, but has negated to take action.

The lawsuit is based on the notion that once a company has been notified of pirate activity, it no longer sits under the safe harbor protection under the Digital Millennium ...