Five U.S ISPs (AT&T, Cablevision Systems Corp., Comcast Corp., Time Warner Cable, and Verizon) have agreed to a copyright alert plan with the A2IM, IFTA, the MPAA (and major members), and the RIAA (and major members).
Here's an excerpt from the press release:
The new Copyright Alert System addresses these problems with a series of early alerts—up to six—in electronic form, notifying the subscriber that his or her account may have been misused for online content theft of film, TV shows or music. It will also put in place a system of "mitigation measures" intended to stop online content theft on those accounts that appear persistently to fail to respond to repeated Copyright Alerts. The system will also provide subscribers the opportunity for an independent review to determine whether a consumer's online activity in question is lawful or if their account was identified in error. There are no new laws or regulations established as a part of this voluntary agreement. Termination of a subscriber's account is not part of this agreement. ISPs will not provide their subscribers' names to rights' holders under this agreement.
For an explanation "mitigation measures," see the "FAQ's on The Center for Copyright Information and Copyright Alert System."