Can an ISP be forced to reveal subscriber information?
Possibly: “The Recording Industry Association of America (RIAA), using a controversial subpoena provision introduced by the 1998 Digital Millennium Copyright Act (DMCA). sought to have Verizon Internet Services reveal the identity of a Verizon subscriber because the subscriber allegedly used KaZaA peer-to-peer software to share music online. Verizon refused to divulge the subscriber’s identity, claiming that the provision didn’t cover alleged copyright-infringing material that resides on individuals’ own computers, it only covers material that resides on an ISP’s own computer. In January 2003 a Judge Bates of the Washington D.C. District Court rejected Verizon’s interpretation of the DMCA subpoena provision, ordering Verizon to reveal the subscriber’s identity. The decision was appealed, and in the intervening time Verizon sought to quash a second subpoena.” – http://www.eff.org/Cases/RIAA_v_Verizon/ The decision is still currently under appeal (July 2003).