Just in time to save the consumer from the changed ways of the RIAA, Methlab Productions has released their PeerGuardian software that blocks transmissions from IP addresses known to be haunted by the music industry.
In the past, the RIAA had claimed that they wouldn't attack consumers, giving them a sort of "non-combatant" status in their war with the "enemy" pirates.
The software package uses a web-based list for submissions of new entries and to keep user's lists up to date.
I do foresee at least one potential problem with allowing contributed addresses, though. If the RIAA were smart, it would start requesting for blockage of the sites with pirated music on it.