After receiving a request by the RIAA to forward illegal download warnings to their users, not one of the 50 top ISP's have complied with the instructions. A recent court ruling prevented ISP's from being forced to hand over such incriminating data.
The request, received in the form of a detailed letter, said "We would like to work with you to supplement our efforts by arranging for ISPs to notify their subscribers who are engaged in infringing activity that this conduct is illegal".
Service providers are aware that the RIAA policy would be voluntary and so are understood to be considering their next move. "We are more than happy to talk with them (RIAA), but it has to as a part of a broader issue." said a Verizon spokeswoman. Source